Nanomaterials, nanostructures and nano-devicesE
Organized nanostructures and nano-objects: fabrication, characterization and applications
Introduction and scope:
The symposium covers all the scientific and technological aspects related to the synthesis, the physical/chemical characterizations, the material properties of semiconductor or metallic nanodots and nanowires, with special emphasis on the multiscale organization and auto-organization of ordered structures, in view of their integration in functional devices.
Due to their appealing size dependent properties, semiconductor and metallic nano-objects (nanocrystals, nanowires) have been predicted to be used as technological boost in various fields including nanoelectronics, optoelectronics, photonics, magnetism, phononics, plasmonics, advanced sensing and photovoltaics. The capability to control size, shape, interface, composition, and doping of these nanoobjects is crucial to finely tailor their properties. Nevertheless, the implementation of these elemental building blocks into functional devices at nano-scale requires precise control of the organization of the nanoobjects in terms of density and relative positioning within well-organized structures, both in plane and in depth. The feasibility to fabricate ordered arrays of nano-objects and to precisely organize the nano-objects on appropriate substrates or inside various matrices is the key issue to support the technological development of new device concepts with predictable characteristics based on these novel nano-materials. The systematic control and the accurate homogeneity of each nanostructure in an organized array are crucial for their exploitation in quantum devices. Following very successful symposia organized in 2012 and 2014, this symposium intends to draw on previous experience. In particular, a special focus on multiscale fabrication, organization and auto-organization is requested by the scientific community working in the field of nanotechnology. The symposium will provide the opportunity to present insights on advanced nanostructures and nano-device architectures at different stages of development.
The symposium is open to all the experimental and theoretical results on organized nano-structures, aiming to control the main parameters of the nano-objects in relation with their tunable properties and functionalities. Thus the symposium is conceived as a platform that gathers researchers coming from academia and industry and promotes interactions among scientists and engineers working on all the aspects of semiconductor and metallic nano-structures, ranging from fundamental physics and material science issues up to the technological implementation toward the final application in functional devices.
Hot topics to be covered by the symposium:
- Synthesis of nano-structures: Top-down and Bottom-up processes
- Nano-structures on surface and in volume
- Self and induced organization of metal and semiconducting nano-structures
- Advanced methodology to control synthesis, positioning, shape, size in nano-structures
- Semiconducting nano-structures for novel logic or memory architectures and for quantum device
- Light emission and optical gain in semiconductor nano-structures
- Metal and semiconducting nano-structures for energy applications: photovoltaic and thermoelectric
- Nano-structures for advanced sensing and plasmonic applications
- Doping issues in nano-structures
Tentative list of invited speakers:
- Ferrarese Lupi, Federico, INRIM, Torino, Italy, “Directed self-assembly for nanofabrication and metrology”
- Sparnacci, Katia, University of University of East Piemonte, Alessandria Italy, “Chemical Surfacemodification”
- Yerushalmi, Roie, Hebrew University of Jerusalem, Israel, “Monolayer Contact Doping”
- Black, Charles, Brookhaven National Laboratory, USA, “Nanostructured materials for solar devices”
- Navarro Urrios, Daniel, ICN2, Barcelona, Spain, “Nanostructured materials for phononics”
- Dohnalová, Kateřina, University of Amsterdam, Holland, “Optical properties of nanostructures”
- Gali, Adam, WIGNER Research Centre for Physics, Budapest, Hungary, “Theoretical Investigation ofnanostructures”
- Hofer, Ferdinand, University of Graz, Austria “Plasmons in Nanoparticles by analytical (S)TEM”
- Stéphan, Odile, Université Paris-Sud, France, “Advanced structural characterizations”
- Guldin, Stefan, UCL, London, UK, "Inorganic Nanoarchitectures by Organic Self-Assembly"
- Norris, David J., ETH, Zurich, Suisse, "Plasmonic properties of nanostructures"
- Jehl, Xavier, CEA-INAC, Grenoble, France, "Single electron effects in nanostructures"
Further invited talks will be selected from outstanding submitted oral contributions.
- Perego Michele - Lab MDM, IMM-CNR, Agrate, Italy
- Schamm-Chardon Sylvie - CEMES/CNRS, Toulouse, France
- Normand Pascal - IMEL NCSR, Athens, Greece
- Pivac Branko - Rudjer Boskovic Institute, Zagreb, Croatia
- Heitmann Johannes - TU Bergakademie, Freiberg, Germany
- Laus Michele - University of East Piemonte, Alessandria, Italy
- Kovalenko Maksym - ETH Zurich and EMPA, Zurich, Switzerland
- Hütten Andreas - University of Bielefeld, Bielefeld, Germany
- Puglisi Rosaria - IMM-CNR, Catania, Italy
- Hourlier Djamila - CNRS-IEMN, Lille, France
- Galli Matteo - University of Pavia, Pavia, Italy
- Estradé Sònia - Universitat de Barcelona, Barcelona, Spain
- Hiller Daniel - IMTEK- Freiburg University, Freiburg, Germany
- Gatel Christophe, University of Toulouse, Toulouse, France
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Nanofabrication: Top-Down and Bottom-Up Processes : Lindner J. K. N.
Authors : Stefan Guldin
Affiliations : University College London, Department of Chemical Engineering, Torrington Place, London, WC1E 7JE, United Kingdom
Resume : Inorganic photonic nanoarchitectures by block copolymer self-assembly The self-assembly of block copolymers allows precise control over structure formation on the 5 - 50 nm, i.e. below the spatial resolution of visible light. In my talk, I want to present strategies on how to exploit these formation principles through co-assembly for inorganic nanoarchitectures with nonetheless distinct optical properties . Control over sub-wavelength properties, such as pore dimensions, pore volume and film thickness of the resulting inorganic films enables the stacking of individual mesoporous layers into a multilayer lattice of alternating high and low refractive index - a mesoporous Bragg reflector . Spontaneous micellisation of an adequate block copolymer system and assembly into a regular lattice-type represents effectively the densest packing of pores, yielding refractive indices as low as 1.13. Loading of the inverse-opal type network with TiO2 nanocrystals results in an optical coating that meets phase and amplitude conditions for interference-based antireflectivity on glass or plastic substrates and maintains its functionality by photocatalytic self-cleaning . Recent efforts in the group aim to generalise this concept for a range of structure directing polymeric host and inorganic guest materials, broaden their functionality and further develop the characterisation tools for mesoporous thin film architectures. References  “Block copolymer self-assembly for nanophotonics” – M. Stefik, S. Guldin, S. Vignolini, U. Wiesner, U. Steiner, Nano Letters, vol. 44, no. 15, pp.5076-5091, 2015.  “Tunable mesoporous Bragg reflectors based on block-copolymer self-assembly” - S. Guldin, M. Kolle, M. Stefik, R. Langford, U.Wiesner, U. Steiner, Advanced Materials, vol. 23, no. 32, pp. 3664-3668, 2011.  “Self-cleaning antireflective optical coatings” - S. Guldin, P. Kohn, M. Stefik, J. Song, G. Divitini, F. Ecarla, C. Ducati, U. Wiesner, U. Steiner, Nano Letters, vol. 13, no. 11, pp. 5329-5335, 2013.  “Ordered mesoporous to macroporous oxides with tunable isomorphic architectures: solution criteria for persistent micelle templates” - H.N. Lokupitiya, A. Jones, B. Reid, S. Guldin, M. Stefik, Chemistry of Materials, vol. 28, no. 6, pp. 1653-1667, 2016.
Authors : Fabian Schütt,* Sören Kaps, Sandra Nöhren, Daria Smazna, Jürgen Carstensen, Yogendra Kumar Mishra, Rainer Adelung
Affiliations : Functional Nanomaterials, Institute for Materials Science, University of Kiel, Kaiserstr. 2, D-24143, Kiel, Germany.
Resume : The fabrication of three dimensional (3D) architectures (such as sponges, foams, aerogels, aerographite, etc.) from 1D as well as 2D nanomaterials is an extensively studied field due to their broad range of applications in the areas of energy storage, healthcare, catalysis as well as environmental protection. However, the utilization of such materials and their extraordinary properties, like the high tensile strength of 63 GPa for CNTs or graphenes lowest electrical resistance, is typically limited by the lack of advanced structural design. Macroscopic foams from such low-D materials are typically manufactured either by rather complicated chemical vapor deposition (CVD) processes or by wet chemical approaches, such as freeze-drying. This study introduces a new strategy for fabricating highly porous (93%) networks from 1D or 2D nanomatrials using a simple dripping procedure as well as sacrificial ceramic templates based on 3D microparticles. Due to the high versatility of this process a combination of different materials can be achieved, leading to complex 3D composite architectures with special properties. It is shown, that in the case of CNTs, self-entangled CNT-networks are homogenously formed around the macroscopic structure of the template during drying. Thereby the mechanical as well as the electrical properties compared to those of the template are increased by several orders of magnitude, resulting in a highly porous, conductive as well as mechanically stable composite structure. Furthermore, the structure-property correlation has been understood. Removing the template results in a highly porous 3D CNT-architecture consisting of self-entangled carbon nanotubes, showing superior mechanical properties compared to those of similar carbon-based structures. References:  Advanced Materials 26, 2014, 6100-6105  Advanced Materials 24, 2012, 3486-3490  Nature Nanotechnology 7, 2012, 562-566  Particle & Particle Systems Characterization 30, 2013, 775-783  Nano Letters 11, 2011, 4288-4292  Manuscript submitted (2016)
Authors : J. Martín, R. Li, A. Nogales, A. Amassian, D.-M. Smilgies, N. Stingelin
Affiliations : Department of Materials, Imperial College London, Exhibition Road, London, SW7 2AZ; Cornell High Energy Synchrotron Source, Wilson Laboratory, Cornell University, Ithaca, 14853, USA; Instituto de Estructura de la Materia IEM-CSIC, C/ Serrano 121, Madrid 28006, Spain; Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia; Department of Materials, Imperial College London, Exhibition Road, London, SW7 2AZ
Resume : Confinement is a universal phenomenom in soft matter. The dynamic and thermodynamic properties of molecular systems undergo strong modifications when they are confined to small dimensions because at this scale, the size of the material conflicts with the characteristic lengthscales of physical process such as crystallization, self-assembly, etc. Thus, these processes are forced to develop in a different manner in order to adequate to the new spatial conditions, which leads to a material with a new physical behaviour and, eventually, to distinct properties1. Typical devices manufactured from π-conjugated molecular materials, such as FET and OPV cells, are based on architectures where the material is processed to have nanoscale dimensions. Therefore, it is to be expected that the material integrating such devices experiences some kind of confinement effect during the processing step, which would influence its microstructure development. However, little attention has been paid so far to confinement effects on the structural features of π-conjugated systems even though it is well known that microstructure determines to a large extent their device performance2. Here we have addressed this issue via the comprehensive study on phase behavior of the model conjugated system p-DTS(FBTTh2)2 as a fuction of T and the degree of confinement (size). p-DTS(FBTTh2)2 is one of non-polymeric molecules showing the highest efficiencies for OPV. As confining medium, we have selected the nanopores of AAO templates3, which have diameters ranging from 25 to 400 nm. The analysis of the microstructure of the material revealed strong confinement effects, i.e. a notably different phase behavior as compared to its bulk counterpart. Deep depressions of crystallization temperature denote the change of nucleation mechanism of confinement crystals. Moreover, a new thermotropic mesophase is observed inside the smallest pores that is absent in the bulk material. More striking is the discovery of a new confinement-induced crystal polymorph. We outline the complete phase behavior of p-DTS(FBTTh2)2 in a temperature-confinement phase diagram. This phase diagram is employed then to design processing protocols that allow the coherent manipulation of the microstructure in the semiconductor. For example, we fully select the crystal texture of our material via selection of the degree of confinement and engineering the crystal nucleation step. Moreover, we are able to also to select the crystal polymorph. 1. Martín, J. et al. Phys. Rev. Lett. 2010, 104, (19), 197801. 2. Treat, N. D.; Stingelin, N.; et al. Nature Materials 2013, 12, (7), 628-633. 3. Martín, J.et al. Nature Commun. 2014, 5.
Authors : Jong Uk Kim, Kwang Su Kim, Hyo Won Tak, Sori Lee, Pil J. Yoo, Tae-il Kim
Affiliations : Jong Uk Kim; Hyo Won Tak; Sori Lee; Tae-il Kim Center for Neuroscience Imaging Research, Institute of Basic Science (IBS), Suwon 440-746, Republic of Korea Jong Uk Kim; Kwang Su Kim; Hyo Won Tak; Sori Lee; Pil J. Yoo; Tae-il Kim School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea Kwang Su Kim; Pil J. Yoo Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon 440-746, Republic of Korea
Resume : Nanofabrication is an inevitable process in nanoscience and nanotechnology. Compared to conventional photolithography, unconventional lithographic techniques, for example nanoimprint, soft lithography etc., have drawn attention for cost effective, reliable process. However, these techniques are limited in scalability due to relatively expensive, complex and time-consuming processes. To challenge this issue, here we suggest a simple yet robust strategy for realizing a high precision temperature controlled rigiflex mold directly amenable to printing process with high resolution and site-specific accuracy. The surface temperature of the mold controlled by localized joule-heating could be perfectly and uniformly tuned over a large surface area (20 mm x 10 mm). To prove the feasibility of versatile utilization of this rigiflex mold, we demonstrated site-selective dewetting and nanoimprint lithography for sub-100 nm scale on a polystyrene (PS) thin film. In particular, compared to other printing techniques reported, this work can offer a highly precise spatial controllability for patterning on specific regions, and it also shows a great potential for large area pattering and hierarchical structuring readily using step-and-repeat processes. The proposed strategy is anticipated to widen its patterning related applications including semi-conductor electronics, transparent electrodes, pressure and electrochemical sensors.
Authors : Matthias Künzle, Thomas Eckert, Tobias Beck*
Affiliations : Matthias Künzle, Tobias Beck*: Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany, email@example.com; Thomas Eckert: Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany;
Resume : Molecular design at the nanoscale enables tuning the properties of functional materials. Binary and ternary nanoparticle superlattices are of special importance because they combine components with different functionalities, leading to emerging collective features. We report on the use of two oppositely charged protein containers, derived from the capsid-forming protein ferritin, as building blocks for a new type of material. Binary assemblies with crystalline order were obtained, forming a tetragonal lattice, and were characterized by X-ray crystallography to high resolution. Moreover, the cavity of the engineered protein containers can be filled with inorganic nanoparticles. Importantly, the assembly of these protein-nanoparticle composites yields highly ordered binary nanoparticle superlattices as free-standing crystals, with up to a few hundred micrometers in size. The assemblies were characterized using SAXS, SEM and EDX. By self-assembly of oppositely charged protein containers with nanoparticle cargo in this way, biohybrid structures are generated with potential application in catalysis, bioelectronics and biomedical use.
Block-Copolymer Self-Assembly and Directed Self-Assembly : Guldin S.
Authors : Federico Ferrarese Lupi
Affiliations : Nanoscience and Materials Division, Istituto Nazionale Ricerca Metrologica, Strada delle Cacce 91, 10135 Torino (Italy) – Email: firstname.lastname@example.org
Resume : The miniaturization process that is currently involving the development of nanotechnology requires the parallel implementation of reliable characterization techniques and suitable standards for the dimensional characterization of structures having minimum features size at sub-10 nm level. Industry and calibration laboratories need lateral length standards at the nanometric level for the resolution certification of a variety of measuring instruments, such as the Scanning Probe Microscopes (SPM), the Optical Phase Shift Microscopes, and the Scanning Electron Microscopes (SEM). The implementation of traceable measurement capabilities in surface analysis, material science and biophysics requires the introduction of new types of reference samples for length metrology at the nanoscale. In particular a new paradigm is necessary for the realisation of nanometric lateral length standards, possibly employing invariants of nature, like self-organized structures at the nanoscale. In this context one interesting solution in order to satisfy this lack is represented by the directed self-assembly (DSA) of DiBlock Copolymers (DBCs) inside gratings of multiple trenches. In this work we demonstrate how the possibility to carefully tune the characteristic dimensions of the nano-domains confined inside periodic gratings allows envisioning a strategy to use the DSA of DBCs as a tool for the fabrication of lateral length standards.
Authors : Katharina Brassat, Daniel Kool, Jörg K. N. Lindner
Affiliations : University of Paderborn, Department of Physics – Nanostructuring, Nanoanalysis and Photonic Materials, Paderborn, Germany; Center for Optoelectronics and Photonics Paderborn CeOPP, Paderborn, Germany
Resume : Nanosphere lithography (NSL) is a well established technique to form large area surface patterns with periodicities in the range of several hundred nanometers, determined by the diameter of nanospheres used. With the self-arranged spheres acting as shadow masks, a large variety of structural motives can be realized by a suitable thermal, plasma or ion beam treatment of spheres prior to a subsequent thin film deposition step. Here, NSL is used in combination with reactive ion etching and subsequent physical vapor deposition of metals (Pt, Ti) in order to form a metal or semiconductor film with an antidot pattern, i.e. a hexagonally close packed arrangement of cylindrical holes. These holes have typical diameters in the range of 300 nm. Block copolymer (BCP) lithography is an emerging self-organization technique by which antidot patterns can be created which are 1-2 orders of magnitude smaller than the ones created by NSL. In this contribution we study the formation of vertical BCP pores on antidot patterned Pt and TiO2 films in order to analyze the influence of NSL pre-patterning on the microphase separation process in PS-b-PMMA block copolymers. A significant difference in the ordering of pores is observed between antidot patterns which are either formed by sputtering of Pt onto NSL masks or by electron beam evaporation of Ti on equivalent masks. The contributions of both, different morphology and chemistry in these antidot patterns on the BCP ordering process are discussed.
Authors : Tommaso Jacopo Giammaria , Federico Ferrarese Lupi , Gabriele Seguini , , Diego Antonioli , Valentina Gianotti , Katia Sparnacci , Michele Laus , Michele Perego .
Affiliations :  Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20846 Agrate Brianza (MB), Italy;  Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Viale T. Michel 11, Università del Piemonte Orientale “A. Avogadro", INSTM, Alessandria 15121, Italy;  Nanoscience and Materials Division, Istituto Nazionale Ricerca Metrologica, Strada delle Cacce 91, Torino, Italy.
Resume : Diblock copolymers thin film have emerged as a cost effective nanofabrication technology because self-assembly (SA) in highly ordered polymeric templates that could be useful in several technological applications. Polystyrene-b-polymethylmethacrylate (PS-b-PMMA) block copolymer (BCP) has been recognize as the material of choice to fabricate lithographic masks because of the possibility to easily control the orientation of the nanostructures with respect to the substrate by means of PS-r-PMMA brush layers (RCP) and to selectively remove one of the blocks of the BCP. In this work, we investigated the influence of the retained solvent amount (θ) on the lateral ordering evolution (ξ) in systems consisting of asymmetric PS-b-PMMA (67 Kg/mol and PS fraction of 70%) films with thicknesses of 30 nm, 70 nm, 100 nm, 130 nm deposited on RCP brush layers with thicknesses ranging from 2 nm to 20 nm. The SA processes was conducted by means of thermal annealing in Rapid Thermal Processing (RTP) machine at 250 °C for 300 s. We demonstrated that at fixed BCP film thickness, the solvent amount (θ) trapped in the RCP BCP system increases as a function of the RCP thickness and, at fixed RCP thickness, θ increases with the BCP thickness. Moreover, we observed that the increasing of θ in the system RCP BCP influence the ξ of the BCP films having thickness of 30 nm while in the other cases the increasing of θ does not influence the ξ of the cylindrical nanostructures.
Authors : G. Claveau, M. Argoud, P. Pimenta Barros, N. Posseme, R. Tiron, X. Chevalier, C. Navarro
Affiliations : CEA-LETI, CEA-LETI, CEA-LETI, CEA-LETI, CEA-LETI,ARKEMA FRANCE, ARKEMA FRANCE
Resume : The 300mm evaluation of a 38nm period lamellar PS-b-PMMA for L/S applications with graphoepitaxy. G. Claveau, M. Argoud, P. Pimenta Barros, N. Posseme, R. Tiron CEA-LETI, MINATEC Campus, 17 Rue des Martyrs, 38054 Grenoble, France X. Chevalier, C. Navarro, ARKEMA FRANCE, Route Nationale 117, BP34- 64170 Lacq, France Directed Self Assembly (DSA) of block-copolymers (BCPs) used as a complementary technique to the 193nm immersion lithography as already demonstrated sub-10nm node applications in both via  and line/space patterning . However several potential issues (pattern fidelity, defectivity, roughness of lines...) are to be overcome before DSA can be applied to the semiconductor industry. The aim of this work is to use the 300mm pilot line available at LETI and Arkema’s advanced materials  to evaluate the performances of a 38nm period lamellar PS-b-PMMA (L38) standard DSA process reported before . We use a graphoepitaxy approach which allows DSA with thicker initial BCP layer, higher multiplication factors and stronger orientation control of lamellae. A systematic CD-SEM review of templates before and after the DSA process was made as a way to associate the performance of the BCP lamellae with the one of the original organic patterns. From this method, beyond the simple CD of PS or PMMA lines, two data are gathered: the roughness and defectivity amount. The roughness evaluation was carried out using a proprietary program called DGmage. The CDSEM image acquisition parameters and post-processing routine (seeding, sum lines, smoothing) were optimized as advised in literature . A Power Spectral Density (PSD) module using the ITRS recommendation as also been implemented, which offers the possibility to select only one relevant frequency regime. A proprietary software from LETI was also developed to register line interruption, line multiplication and isolated line block inside automatically registered CDSEM image of 100K (FOV of 1µm²). In the end, values of CD, roughness and defectivity of PMMA lines are extracted from this review and are used to draw out the process window, function of the CDguide, of this graphoepitaxy process. On commensurate patterns, we report a mean CD of PMMA lines of 11nm (3σ=0.6nm), a LWR of 1.0nm (3σ) and a LER of 1.9nm (3σ) after PSD treatment (25 images statistic) at low frequency regime. This methodology will be applied from now on to determine the optimum DSA process parameters as well as to further illustrate the ability of the BCP to accommodate and improve on a deliberately implemented roughness variation of guiding patterns. Overall, this work further illustrates the possibility for DSA of lamellar polymer to be implemented in the industry using a graphoepitaxy approach. References:  Tiron, R. et al. Proc. of SPIE 2015, Vol. 9423, 942317.  Bates, Christopher M., et al. Macromolecules Vol.47, 2-12, (2014).  R. Tiron et al, Proc. of SPIE 2012, Vol. 8323, 8323-23  Claveau, G. et al., Proc. Of SPIE 2016, Vol 9779, 9779-48  Azarnouche, L. et al. Journal of Applied Physics 111, 084318 (2012).
Authors : Gregory Blachut, Stephen Sirard, Michael J. Maher, Yusuke Asano, Yasunobu Someya, Austin P. Lane, William J. Durand, Roel Gronheid, Diane Hymes, Christopher J. Ellison, C. Grant Willson
Affiliations : Gregory Blachut (The University of Texas at Austin); Stephen Sirard (Lam Research); Michael J. Maher (The University of Texas at Austin); Yusuke Asano (The University of Texas at Austin); Yasunobu Someya (The University of Texas at Austin); Austin P. Lane (The University of Texas at Austin); William J. Durand (The University of Texas at Austin); Roel Gronheid (imec), Diane Hymes (Lam Research), Christopher J. Ellison (The University of Texas at Austin); C. Grant Willson (The University of Texas at Austin)
Resume : The directed self-assembly (DSA) of a 20 nm full pitch lamellar-forming, silicon-containing block copolymer (BCP), poly(4-methoxystyrene-b-4-trimethylsilylstyrene), was performed on 300 mm wafer scale using both chemoepitaxy and hybrid grapho-/chemo- epitaxy. 4x and 5x density multiplication of the initial prepattern was demonstrated with these process flows. Due to the etch contrast between organic polymers and silicon-containing polymers, the organic BCP domain could be selectively removed to yield high aspect ratio structures suitable as lithographic masks. To optimize the process flows, the prepattern pitch, feature width, BCP film thickness, and surface chemistry of the prepatterns were systematically optimized. Compared to the pure chemoepitaxial flow, the hybrid grapho-/chemo- epitaxial flow had fewer defects and a higher tolerance for process parameter variation. To further understand the relationship of the guiding structure to the BCP and to investigate the BCP three dimensional morphology in the hybrid epitaxy flow, TEM cross-sections with EELS mapping were performed at regions of interest. The learning from this study was used to optimize the DSA of an even smaller 10 nm full pitch silicon-containing BCP.
Thermoelectric Applications : Ferrarese Lupi F.
Authors : D. Navarro-Urrios 1; N. E. Capuj 2; J. Gomis-Bresco 3; M. F. Colombano 1; P. D. García 1; M. Sledzinska 1; F. Alzina 1; A. Griol 4; A. Martinez 4; C. M. Sotomayor-Torres 1,5
Affiliations : 1 Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193 Barcelona, Spain 2 Depto. Física, Universidad de la Laguna, La Laguna, Spain 3ICFO-Institut de Ciencies Fotoniques and Universitat Politcnica de Catalunya, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain 4Nanophotonics Technology Center, Universitat Politècnica de València, Spain 5Catalan Institute for Research and Advances Studies ICREA, Barcelona, Spain
Resume : Miniaturized self-sustained coherent phonon sources, also known as “phonon lasers”, are interesting for applications such as mass-force sensing, intra-chip metrology and intra-chip time-keeping among others. We will review several mechanisms and techniques that can drive a mechanical mode into the lasing regime by exploiting the radiation pressure force in optomechanical (OM) cavities. We will specifically focus on a novel and efficient strategy demonstrated in OM crystals using the radiation pressure as the driving force of the motion. The pumping mechanism is based on a self-pulsing (SP) limit cycle, which is a spontaneous process triggered within the optical cavity that modulate the intracavity radiation pressure force in resonance with a mechanical mode. Self-sustained mechanical oscillations of modes up to 0,2 GHz are achieved if one of the low harmonics of the modulated force is resonant with a mechanical eigenstate. We will discuss our strategies to further speeding up of the SP dynamics and reach the GHz regime, where the lack of good quality and miniaturized sources is a severe issue.
Authors : Heinz Renner, Vincent Linseis, Kornelius Nielsch
Affiliations : Linseis Messgeräte GmbH, Vielitzer Str. 43, 95100 Selb; University of Hamburg, Institute of Applied Physics, Hamburg;
Resume : Due to new research efforts in various fields with a focus on size effects, there is a growing need for measurement setups dedicated to samples with small geometrical dimensions like thin films and nanowires with considerably different physical properties than bulk material. The characterization of these samples is important to learn more about their structure and conduction mechanism but also important for technical applications e.g. in the semiconductor industry. We report about new developments to characterize thin films in the range from 10 nm to 200 µm. The first one is a Transient Thermoreflectance Method which enables the measurement of the thermal conductivity on thin films with high accuracy. On various application examples it can be proved that the thermal conductivity is strongly dependent on the thickness of the material. The thermal conductivity of some thin film thermoelectric materials decreases with decreasing sample thickness by one or two orders of magnitude. The second approach is a chip based system which measures simultaneously the electrical and thermal conductivity, the Seebeck Coefficient and the Hall Constant of a thin film sample in the temperature range from liquid nitrogen up to 350°C. Due to the simultaneous measurement at only one sample, errors caused by different sample compositions, different sample geometries (thickness) and different heat profiles can be avoided. The system consists of two main parts, a structured Si-wafer and a suitable measurement setup . The sample deposition and handling is kept easy and optimized to meet a very broad range of use.
Authors : Isis Maqueira-Albo, Alex Barker, Mario Caironi
Affiliations : Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Via Pascoli 70/3 – 20133 – Milano (Italy)
Resume : Thermoelectric devices represent a clean way to convert derived heat into electricity but their efficiency depends critically on the material performance. Polymers potentially offer some peculiar features compared to inorganic materials for thermoelectrics (low thermal conductivity, production cost and solution-processability). Notably, PEDOT:PSS exhibit a high electrical conductivity (σ), therefore understanding its thermal transport is crucial for further uses. Only few methods are established for that purpose but expensive dedicated instrumentation and mathematical modelling are required. We studied through a pump-probe technique the thermal properties of different formulations of conductive PEDOT:PSS. The main advantage is that it opens up opportunities to study thermal properties of thin film polymers with standard pump-probe setups. Our approach is to fit with the same parameters (polymer thermal conductivity and the interfacial thermal resistances) the data obtained from different material thicknesses considering one-dimensional diffusion equation of the heat flow within the polymer. To validate our approach we used PMMA and the results are in agreement with the reported ones. We further tested three different commercial PEDOT:PSS formulations. The formulation Orgacon™ICP-1050 (in-plane σ//=11.3 S/cm), has the lowest value of thermal conductivity, 0.339 Wm-1k-1. The other two formulations show a little higher values of 0.446 and 0.461 Wm-1k-1 for the Clevios™PJet700 (σ//=267.1 S/cm) and Orgacon™IJ-1005 respectively (σ//=462.8 S/cm).
Authors : M. Dialameh 1&2, F. Ferrarese Lupi 1, F. Zanenga 3, G. Seguini 3, M. Perego 3, N. De Leo 1, L. Boarino 1
Affiliations : 1 Istituto Nazionale di Ricerca Metrologia (INRIM) 2 Politecnico di Torino 3 Laboratorio MDM, IMM-CNR
Resume : Recently the fabrication of nanostructured holey silicon membranes received a large attention since they were recognized as fundamental platform for studying the electrical and thermal conductivity across superlattices and nanoscale materials. In this work we systematically investigated the influence of the geometrical parameters (i.e. pore diameter and film thickness) of cylinder-forming PS-b-PMMA block copolymer (BCP) films on the etch rate and aspect-ratio into a silicon substrate. The fine tuning of the characteristic dimensions (between 10 nm and 30 nm) of the BCP masks has been obtained by changing the molecular weight (Mn) of the PS-b-PMMA in a range between Mn = 54 Kg/mol and Mn = 102 Kg/mol. The phase separation and the self-assembly process were achieved by driving the polymeric masks over the glass transition temperature using a Rapid Thermal Processing machine. The pattern transfer through the BCP masks into Silicon substrate was performed by means of a Reactive Ion Etching (RIE) process using a cryogenic mixing mode of SF6/O2 gases. As result of this work, holey silicon membranes having different pore diameters and depth have been obtained and characterized by means of ellipsometry and X-ray reflectivity (XRR) techniques. Acknowledgment: This work has been done under framework of 3DMetChemIT project (EMPIR project 14IND01).
Authors : Sayak Dutta Gupta, J. B. M. Krishna, Mallar Ray
Affiliations : Indian Institute of Engineering Science and Technology, Shibpur; UGC-DAE-CSR, Kolkata Centre; Indian Institute of Engineering Science and Technology, Shibpur
Resume : Composite thin films and tablets of luminescent silicon nanoparticles (NPs) dispersed in two different matrices – polyaniline (PANI) emeraldine base (PANI EB) and PANI emeraldine salt (ES) were prepared by simple physical mixing. Blue insulating PANI EB were synthesized by oxidative polymerization of aniline by ammonium persulfate (APS) in presence of hydrochloric acid (HCl) followed by complete dedoping by ammonium hydroxide. Controlled primary doping has been achieved by protonating the EB with measured camphor sulphonic acid (CSA) to yield green conducting PANI ES. The prepared PANI EB and ES have been physically mixed in solid state with silicon NPs prepared by HF etching and piranha etching of ball milled commercial Si powder to prepare the composites. The XRD of PANI ES shows an enhanced crystallinity compared to the EB which can be attributed to the CSA doping. This improved crystallinity plays a pivotal role in the manifold conductivity increase in the ES which has been measured by Current-Voltage characterization of pellets of the samples at room temperature. I-V characterization of the pellets of the composites prepared by isostatic pressing reveals that while incorporation of the NPs in the EB has significantly boosted its conductivity, there has not been any major decrement of the same in the ES. Besides, a considerable change in the Seebeck coefficient of PANI and the composites has been achieved at around room temperature. Introduction of Si NPs in PANI ES has resulted in an increase of Seebeck coefficient by 1µV/K at room temperature. These results point towards a potential thermo-electric material with significantly high figure of merit, which we are presently developing.
Photovoltaic Applications : Navarro-Urrios D.
Authors : Pawel Majewski, Atikur Rahman, Andreas C. Liapis, Antonio Checco, Kevin Yager, and Charles T. Black
Affiliations : Brookhaven National Laboratory, Upton, NY 11973 USA
Resume : We use block copolymer self assembly to precisely define and construct functional surface coatings for solar materials. Block copolymer self assembly is a robust method for generating regular, uniform patterns at the 10 nm length scale over arbitrarily large areas and is easily integrated with thin-film processing. We fabricate densely-packed, sub-wavelength nanotextures on top of silicon solar cells to impart broadband antireflection, reducing the reflectance of normally-incident light to less than one percent for wavelengths from 400 nm to one micron, and maintaining less than 4 percent reflectance for incidence angles as high as 60 degrees. The performance of solar cells textured this way improves by 50 percent compared to that of untextured devices. Similarly textured surfaces eliminate reflections from glass and plastics, including polyimide, kapton, and teflon. Simulations of these structures, based on an anisotropic effective medium, accurately reproduce the measured optical properties, and show that our approach yields a refractive index profile very near the optimum for minimizing reflections. Texturing surfaces with a high density of nanostructures also imparts superhydrophobicity. These coatings maintain extreme water repellency under a broad range of environmental conditions where superhydrophobic materials are prone to failure, including high droplet impact velocity, high pressures, high humidities, and large droplet-surface temperature differentials. This research used resources of the Center for Functional Nanomaterials, which is a U.S. DOE Office of Science Facility, at Brookhaven National Laboratory under Contract No. DE-SC0012704
Authors : R. A. Puglisi, S. Caccamo and A. La Magna
Affiliations : Istituto per la Microelettronica e Microsistemi (IMM), Consiglio Nazionale delle Ricerche (CNR), Strada Ottava 5 Zona Industriale, 95121, Catania, Italy.
Resume : Phase-separated polymers and self-assembled monolayers are scientifically intriguing and technologically important examples of self-assembling because they provide a general strategy for nanofabrication and processing. In particular phase-separated polymers have been used as building blocks for nanolithography allowing to reach feature sizes as small as 14nm. This technology has been exploited to construct, among the others, nanoholes on the Si surface, which represent the negative structure of the nanowires, very popular in photovoltaics for their exceptional light properties, but more robust and then easily embeddable in the devices. The first part of the talk gives a brief overview on the optical management ability of such nanostructures when interacting with solar light. The second part of the talk discusses the self-assembling mechanism producing molecular monolayers on the Si surface. In particular when phosphorus based esters are used they can work as dopant sources, providing a cost-effective and easy alternative to standard doping methods. A review of the most interesting results on molecular monolayer doping of Si will be provided, focusing on the molecule/Si properties. The third part will present our recent works on the combination of these two self-assembling processes in the fabrication of Si nanohole solar cells and on the morphological and electrical characteristics of the materials and final devices.
Authors : MICHELE PEREGO (1), GABRIELE SEGUINI (1), ELENA CIANCI (1), JACOPO FRASCAROLI (1), MONICA CERESOLI (1), SABINA SPIGA (1).
Affiliations : (1) Laboratorio MDM, IMM-CNR, via C. Olivetti 2, 20864 Agrate Brianza (Italy)
Resume : Sequential infiltration synthesis (SIS) allows the growth of inorganic materials into polymeric materials by infiltrating precursors from the gas phase in the polymer template. Combined with the micro phase separated nanostructures resulting from the block copolymer (BCP) self-assembly, SIS elective binds the precursors to only one domain resulting in the formation of an inorganic nanostructure mimicking the original block copolymer template. This strategy provides the opportunity to fabricate a hard mask with increased etch resistance for lithographic application. The SIS process using trimethylaluminum (TMA) and H2O, as metal and oxygen precursors respectively, in self-assembled polystyrene-b-polymethylmethacrylate (PS-b-PMMA) BCP films was established as a model system for the formation of Al2O3 nanostructures that well reproduce the initial morphology of the PMMA phase. Actually the thermal stability of the polymeric nanostructures limits the processing temperature during the infiltration process and consequently the application of the SIS technique is limited to highly reactive metal precursors, such as TMA. In order to expand SIS capabilities and increase the library of inorganic nanostructures that can be fabricated with this technology, the crucial step is the employment of more reactive oxidant precursors such as O3. This work reports a comprehensive morphological (SEM, SE, AFM) and chemical (XPS) characterization of Al2O3 nanostructures synthesized using the O3-based SIS process in self-assembled lamellae forming PS-b-PMMA thin films. The comparison with the H2O-based process is used to validate the possibility to use O3 as oxidant precursor in SIS, effectively expanding the possible range of precursors for the fabrication of inorganic nanostructures. In view of the possible lithographic application it is worth to note that the use of lamellar forming BCP thin films, with nanodomains perpendicularly oriented with respect to the underlying substrate, provides an interesting option for the fabrication of hard masks, since offers the possibility to synthesize Al2O3 nanostructures with high aspect ratio. The thickness and width of the resulting Al2O3 lamellae are investigated in details as a function of the processing condition, demonstrating the capability to finely tune the dimension of the Al2O3 lamellae while maintaining the original periodicity of the polymeric template.
Authors : A.Taurino1, M. Catalano1, M. Lomascolo1, A. Cretì1, A.Cola1, Z. Che2, M. J. Kim2, V. Tasco3, A. Passaseo3, I. Tarantini4
Affiliations : 1 CNR IMM, Institute for Microelectronics and Microsystems, Via Monteroni, I-73100 Lecce, Italy; 2 Dep of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080, USA; 3 CNR NANOTEC Ist Nanotecnol, Polo Nanotecnol, Via Monteroni, I-73100 Lecce, Italy; 4 Univ Salento, Dip Mat Fis Ennio De Giorgi, I-73100 Lecce, Italy.
Resume : InAs/AlGaAs quantum dots (QDs) system, for Enlarged Bandgap Intermediate Band solar cell (IBSCs ) applications, represents an interesting alternative to the most common InAs/GaAs system since improved efficiency is theoretically expected for EG (energy gap of the host barrier material) as large as 1.95 eV . Nevertheless, some growth issues arise due to different mobility of In adatoms on Al-containing surfaces, resulting in a rough interface between AlGaAs and InAs, which negatively affects the growth of uniform and pseudomorphic QDs. In this work, we analyse the structure of self-assembled QDs, grown by following a gradual composition evolution from a quaternary (AlInGaAs) to ternary (InGaAs) and finally binary (InAs) compound. This growth procedure, together with the intrinsic mechanism of QDs formation, leads to a complex chemical and structural profile, which strongly affects the electro-optical properties of the system. A detailed scanning transmission electron microscopy (STEM) study was carried out in order to assess the structural and chemical properties of the QDs layers. In particular, high resolution STEM images and energy dispersive X-ray point spectra, scan profiles and maps allowed to define the compositional and strain distribution within these complex nanostructures and to correlate these results with the electro-optical performances of the related IBSCs.  Luque A., Martí A. The Intermediate Band Solar Cell: Progress towards the realization of an attractive concept. Adv. Mat. 22, 160-174 (2010)
Authors : E. Torralba-Penalver, S. Bastide, C. Cachet-Vivier, S. Le Gall*, R. Lachaume*, M. Halbwax**, V. Magnin**, J. Harari**, J.-P. Vilcot**
Affiliations : Institut de Chimie et des Matériaux Paris-Est, CNRS, Univ. Paris-Est, Thiais, France ? email@example.com ; * Génie Electrique et Electronique de Paris, CNRS, SUPELEC, Univ. Paris-Sud XI, Gif-sur-Yvette, France ? firstname.lastname@example.org ; ** Institut d?Electronique, Microélectronique et Nanotechnologies, CNRS, Univ. Lille1, Villeneuve d?Ascq, France ? email@example.com
Resume : Metal Assisted Chemical Etching (MACE) of Si has attracted the attention of academy and industry during the last decades as an efficient low-cost wet etching method to produce Si nanostructures with high aspect ratios (HAR). Several noble metals are known to be effective catalysts for MACE: Ag nanoparticles (NPs), for example, provide an extremely localized etching with the formation of mesopores or Si nanowire arrays; contrarily, MACE with Pt NPs is rather delocalized, resulting in the formation of large pores whose potential application in Si surface structuration has received less attention. In this work, MACE with Pt NPs under an applied external bias is presented as a novel approach to synthesize HAR Si nanostructures of controlled size and shape, with clear application as built-in blocks for photovoltaic devices, the reflectivity being < 3 % vs. ~10 % for the state of the art texturization technique (inverted pyramids). A combination of voltammetry, impedance spectroscopy and band bending modelling allowed complete physicochemical characterization of this MACE process. This simple method allows straightforward control of the pore morphology, such that nanostructures ranging from straight mesopores to cone-shaped macropores are readily obtained as Si is biased from negative to positive potentials. Because such morphologies are difficult to obtain even with techniques like cryogenic plasma, etching MACE with Pt may have a strong potential for Si surface structuration.
Authors : A.E.Muslimov
Affiliations : IC RAS
Resume : The evolution of a terrace-step nanostructure (TSN) on the sapphire (0001) surface misoriented by an angle of 0.1° with respect to the m- plane was observed by atomic force microscopy (AFM) at temperatures from 1273 to 1673 K. It was established that, with an increase in the annealing temperature to 1373 K, the step height attains 0.44 nm at a distance of 220 nm between steps; i.e., heating by 100 K doubles these parameters. In this case, the relief periodicity is retained. Rapid cooling of the substrate to 973 K leads to partial freezing of the surface structure, which makes it possible to observe the transition from one TSN to another. It was established that two steps coalescence upon annealing to 1373 K toward the m- plane, which has the lowest rigidity and, consequently, the lowest atomic density. The coalescence of two steps at a specified temperature is completed at a sufficiently large distance between the steps, at which their interaction energy is negligible. Upon further annealing of the samples above 1373 K, the steps overgrow to 1 nm; however, their periodicity is broken in this case.
Authors : Iu.N. Makogon, S.I. Sidorenko, R.A. Shkarban
Affiliations : Kyiv Polytechnic Institute, National Technical University of Ukraine, 03056, Prospect Peremogy 37, Kyiv, Ukraine, firstname.lastname@example.org
Resume : One of the ways to increase the thermoelectric coefficient efficiency (ZT) is the application of CoSb3 antimony (conception the G. Slack). The transition to nanoscale materials can further increase ZT due to increasing of the structure defectiveness. In this work we investigated the laws of the thermo induced phase and composition formation of 30 nm thick Co-Sb nanoscaled films with concentration of Sb in the range of 65 at.% – 81 at.%, obtained by molecular beam deposition onto SiO2(100 nm)/Si(001) substrates. It established, deposition onto the substrate at room temperature, followed by heating after the crystallization, leads to the formation of x-ray-amorphous state. At heating temperature above 150оС it is occurred crystallization of amorphous state of the films and expands the region of homogeneity CoSb3 phase (75-80) atm.% Sb. After the increasing of the substrate temperature to 200°C in the Co-Sb films, the crystal state is formed, and the laws of phase formation are determined by the sequence that is analogical to the diagram of phase equilibrium for the bulk state of Co-Sb system with the formation of the homogenous CoSb3 phase under the ~75 at.% of Sb. That the CoSb3 based are thermally stable up to ~300°C. Heat treatment of the Co-Sb films with Sb concentration of 65 at.% to 81% as in vacuum and in nitrogen atmosphere under the temperatures, higher than 300°C, leads to the passing of the phase transition and structural change because of increasing ability of the Sb atoms to sublimation. The activation energy of the Sb sublimation process was determined on the rate of the Sb sublimation at the different annealing temperatures according to the Arrhenius equality. It is found that a more intensive process sublimation Sb upon annealing above 300°C of amorphous films is reflected in lower (2-3 times) the activation energy sublimation Sb compared to films with crystalline state, wherein the chemical bonds are already formed. The change of phase composition by sublimation in films affects the level of stress. Shown, that after deposition in the films it is observed a slight level of tensile stress ~1 GPa, which raises after thermal annealing up to ~5 GPa and is accompanied by appearing of pores and cracks in the film. The authors would like to thank Prof. M. Albrecht and Dr. G. Beddies and workers from Chemnitz University of Technology (Germany) for sample preparation, assistance in conduction of investigations and discussion of results. This work was financially supported by the Deutsche Akademischer Austauschdienst (DAAD) in the frame of the Leonard-Euler-Program (Grant No. 08/01145 and No. 50744282).
Authors : Pavel V. Krasovskii (1), Andrey V. Samokhin (1), Andrey A. Fadeev (1), Mikhail A. Sinaiskiy (1), R. N. Rizakhanov (2).
Affiliations : (1) A.A. Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Leninskii pr. 49, Moscow 119991, Russia; (2) SSC Keldysh Research Centre, Onezhskaya 8, Moscow 125438, Russia.
Resume : Herein are presented analytical studies of the chemical compositions and morphologies of the pseudoalloy nanoparticles in the W–Ni–Fe ternary system. The nanoparticles have been produced in a DC thermal plasma reactor with confined plasma jet. The design of the product nanoparticles is assessed in the context of their promising use for compacting/sintering bulk nanostructured heavy alloys. The focus is on the formation of core/shell structures and surface alloys on an individual particle level, as well as the compositional variability between particles in the material. A combination of analytical techniques is used, including an analytical electron microscopy (AEM, STEM-EDX, HAADF), scanning Auger microprobe (FE-SAM) in conjunction with Ar ion sputtering, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy with X-ray energy dispersive analysis (SEM-EDX). The obtained results provide an insight into the possible mechanisms for the growth of the alloy nanoparticles in the rapidly cooling thermal plasma environment.
Authors : S.Costanzo, G.Simon, Ph. Colomban, I. Lisiecki.
Affiliations : Sorbonne Universités, UPMC Univ Paris 06, UMR 8233, MONARIS, 4 Place Jussieu, 75005, Paris, France CNRS, UMR 8233, MONARIS, 4 Place Jussieu, 75005, Paris, France
Resume : Revisiting the chemical reduction approach of Co(AOT)2 precursor (AOT= bis(2-ethylhexyl)sulfosuccinate) by NaBH4,1 we highlight a novel synthetic strategy based on the change of the solvent to accurately control the size of Co nanocrystals (NCs) from 3.9 to 9.3 nm and their 2D and 3D ordering. The evolution of the NC size with the solvent is explained by solvent mediated ligand-ligand interactions using Hansen solubility parameters, this allows to predict the NC diameter using equation log (d/nm) = 0.944 ? 0.211 log (?12/Jmol-1) within a precision of 1 nm. (2) Due to the possibility we have to replace the AOT ligand by the strong-binding dodecanoic acid, Co NCs are characterized by long-term stability against oxidation and coalescence of the metallic NCs, whatever their size is. Two (2D) and three (3D) ordered assemblies (supracrystals) are prepared by dropwise deposition and by immersing process, allowing TEM and Raman (low wavenumber) characterization.(3) These NCs are poorly cristallized (fcc polycristals), an annealing process give us a well cristallized NCs. We developed also a protocol of controlled oxidation in order to have a core/shell structure made up from Co@CoO stables and in solution. Ordered assemblies are prepared also and characterized with Transmission Electron Microscopy and Small-Angle-X-Ray-Scattering. 1- I. Lisiecki and M. P. Pileni, Langmuir 19, 9486 (2003). 2- I. Lisiecki, P.A. Albouy and M.P. Pileni Adv. Mat. 15, 712, (2003) 3-S.Costanzo, G.Simon, J.Richardi, Ph. Colomban and I.Lisiecki, submitted.
Authors : Ana M. L. Sousa, Jakub Dostalek and K. H. Aaron Lau
Affiliations : University of Strathclyde, Glasgow, UK; Austrian Institute of Technology, Vienna; University of Strathclyde, Glasgow, UK
Resume : Biological nanopores control the specific transport of diverse molecules across different biological compartments. Mimicry of such pores could open up selective and efficient molecular separation. Current techniques such as nanopore analytics focus on using small pores (<10 nm) for controlling and sensing molecular diffusion, but the characterisation and control of the mass transport of macromolecules using larger nanopores are less developed. Towards developing such nanopores for macromolecular transport, we demonstrate how the diffusion of labelled proteins through nanopore channels may be tracked by exploiting nanoscale confined illumination in a nanoporous planar optical waveguide. We fabricated nanoporous alumina (NPA) waveguides with pore diameters matching those of the nuclear pore complex (30-50 nm). The pores were functionalised with poly(ethylene glycol) (PEG) to decrease the nonspecific binding of proteins. The diffusion of proteins of different sizes and net charges as well as free dyes was characterised. As control, the pores were closed by addition of a poly(tannic acid) crosslinked matrix in order to measure the diffusion of the molecules only on the surface of the NPA film. The surface diffusion on top of the closed pores showed similar time constants for all molecules despite their differences. However, the diffusion of the free dye through the open pores was faster than for the proteins. Proteins with the same molecular weight but different net charges showed different time constants because of ionic interactions that can restrict pore entry. This system brings a new concept of measuring molecular diffusion through nanopores which can be invaluable for the development of biomimetic macromolecular transport.
Authors : S. Kratro
Affiliations : Department Electrophysics, Faculty of Radiophysics,Electronics and Computer Systems, Taras Shevchenko National University of Kyiv
Resume : Label-free DNA sensors based on sapphire substrate were fabricated and electrochemically characterized. A low resistivity (0.01-0.02 Ω cm) ptype Al2O3 wafer (100 orientation) was electrochemically anodized in an ethanoic hydrofluoric acid (HF) solution containing ethanol to construct the sapphire substrate layer with pore diameter of about 25 nm. The intrinsic negative charge of the DNA backbone was ex ploited to adsorb 26 base pairs of probe DNA (pDNA) into the PPy film by applying positive bias forming the nPS/PPy+pDNA layer.
Authors : Bruno Pescara [1, 2, 3], Katherine A. Mazzio [2, 3], Klaus Lips [2, 3, 5], Simone Raoux [2, 3, 4].
Affiliations : 1 Institute of Chemistry and Biochemistry, Faculty of Mathematics and Natural Science, Freie Universität Berlin 2 Energy Materials In-Situ Laboratory, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH 3 Institut für Nanospektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH 4 Institute of Physics, Faculty of Mathematics and Natural science, Humboldt-Universität zu Berlin 5 Institute of Physics, Faculty of Mathematics and Natural Science, Freie Universität Berlin
Resume : Nano-structured materials like quantum dots or quantum wires exhibit a wide range of size dependent properties relative to their bulk counterparts, including reactivity, structural stability, optical, and electronic behavior. Group IV nanostructured materials, such as silicon and germanium nanoparticles, offer particularly intriguing opportunities. In their bulk form, both germanium and silicon are indirect band gap materials. However, in their nanocrystalline forms, they can exhibit quantum confinement effects that lead to direct band gap optical transitions in the visible region. These group IV nanomaterials are of interest as environmentally friendly substitutes for semiconductors containing heavy metals in energy conversion and storage applications, such as catalysts for solar fuel production, electrodes for lithium ion batteries and thermoelectric materials. An important prerequisite for these applications is the ability to controllably synthesize Ge nanoparticles. Traditionally, most synthetic methods for germanium nanocrystals have relied on physical methods, such as vapor phase deposition, laser ablation, and various epitaxial methods. These synthetic paths typically require high temperatures and vacuum processes, which can make them expensive, complex, and difficult to scale up, in addition to exhibiting a low degree of morphological control. Solution-based syntheses are an attractive alternative due to their potential of affording high quality nanocrystals with the opportunity for size tunability and surface modifications, in addition to their scale up potential. Germanium nanocrystals have previously been prepared using a variety of solution-based methods, but these reported syntheses usually share one or more of the following issues: presence of hazardous chemical reagents or byproducts, extreme reaction conditions, low yields, and poor morphological control. Ge is strongly covalent, which necessitates a high crystallization temperature and strong reducing agents are typically required to produce crystalline Ge nanoparticles. Moreover, the most common germanium salt reagents require harsh reaction conditions and chemicals, like metallic sodium or sodium naphthalide, to reduce them to elemental germanium. Here we describe the synthesis of germanium nanocrystals with diameters in the range of 20-70 nm via a solution-based “heat up”, and “hot injection” methods, within a sulfur copolymer matrix at relatively low temperatures (T<300° C). Different polymer precursors have been investigated to assess their role in size and morphology control, as well as how they influence the reduction process. Data suggests that the sulfur acts as a reducing agent either via radical or Lewis acid-base interactions. Stabilization of an intermediate germanium species is achieved by using copolymers with lone pairs both in the precursor synthesis and the polymeric matrix, due to their ability to coordinate to germanium. The synthetized nanocrystals exhibit low stability in air and they undergo fast oxidation. Therefore after purification, ligand exchanges were performed on the nanocrystals. These ligands serve as capping agents enhancing the stability in air of these particles by reducing the rate of oxidation, while simultaneously providing tunable solubility in different media. The resulting nanocrystals are characterized with standard lab-based techniques such as Uv-Vis Spectroscopy, Nuclear Magnetic Resonance, Infra-Red Spectroscopy, Transmission Electron Microscopy, Selected Area Electron Diffraction, X-ray Diffraction, as well as synchrotron based analytical methods like Small Angle X-ray Scattering and Anomalous Small Angle X-ray Scattering.
Authors : Romuald B. Beck, Paweł Korb, Kamil Ber
Affiliations : Institute of Microelectronics & Optoelectronics, Warsaw University of Technology Koszykowa 75; 00-662 Wwarsaw, Poland
Resume : Studying behavior of nanocrystals in amorphous matrix is a very complex and sensitive task. This is particularly challenging for cases in which the matrix is of the same or similar chemical nature as nanocrystals. A very good example of such a case is studying silicon nanocrystals in silicon ultrathin layers. Analysis of complex processes that potentially take place during high temperature treatments, namely: recrystallization, amorphization, oxidation of both amorphous and crystalline silicon, is of crucial importance for many technologies and application oriented researches. Spectroscopic ellipsometry, if carefully used, can provide simultaneously many important data on changes in structure and composition of the studied structures for very complex (even multilayers’) structures both, quantitatively as well as qualitatively. Taking into account that this method is nondestructive, very fast and can provide data for very complex (even multilayers’) structures it seems astonishing that this method is so seldom used, especially that otherwise would need to use number of different, destructive, time consuming and costly techniques. In this work we will present the results obtained using this technique in studies on effects of high temperature treatments of structures with single ultrathin PECVD silicon layer on monocrystalline substrates or containing double ultrathin barrier dielectric layers with ultrathin PECVD silicon.
Authors : 1) R. Mroczyński, A. Mazurak, J. Jasiński, R.B. Beck, 2) S. Kano, H. Sugimoto, K. Imakita, M. Fujii, 3) J. Valenta
Affiliations : 1 Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland 2 Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501, Japan 3 Charles University in Prague, Faculty of Mathematics and Physics, Ke Karlovu 3, CZ-121 16, Prague
Resume : For the past several years silicon nanocrystals (Si-NCs) embedded in dielectric layers have been extensively investigated for potential applications in the fields, such as optoelectronics and photonics. The literature reports that materials which are composed of alternating layers of Si-NCs and dielectric films exhibit an increased optical band-gap with decreasing NCs size. In this work we develop the technology of Metal-Insulator-Semiconductor (MIS) structures with Si-NCs films embedded in silicon oxide (SiOx) and hafnium oxide (HfOx) ensembles. In contrary to standard methods of Si-NCs formation by means of Plasma-Enhanced Chemical Vapor Deposition (PECVD) of amorphous silicon (a-Si) with following high-temperature recrystallization/annealing processes, in the course of this study colloidal Si-NCs fabricated by chemical synthetic method were used. The all-inorganic Si-NCs have very heavily B and P doped shells, which induce negative potential on the surface and prevent the agglomeration by electrostatic repulsions. Silicon oxide and hafnium oxide thin films have been fabricated by means of PECVD and of radio frequency (RF) reactive magnetron sputtering process, respectively. Fabricated in the course of this work MIS structures have been investigated by means of structural, optical and electrical characterization. Advanced characterization methods and equipment have been used, namely: spectroscopic ellipsometry (SE), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) microanalyzer, capacitance-voltage (C-V), as well as current-voltage (I-V) measurements. All observations and findings will be carefully examined and described in order to formulate the concluding remarks on results after subtle structural and electrical characterization and potential applications of studied MIS structures.
Authors : M. Szkoda(1), A. Lisowska-Oleksiak(1), K. Siuzdak(2)
Affiliations : (1) Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland; (2) Center for Plasma and Laser Engineering, The Szewalski Institute of Fluid Flow Machinery, ul. Fiszera 14, 80-231 Gdansk, Poland
Resume : Hybrid materials consisting of electroactive polymers and inorganic semiconductor attract attention because of their potential use in electrocatalysis, sensors and energy storage and conversion devices. Among the commonly used conducting polymers, pEDOT has received considerable attention in recent years due to the low oxidation potential, high conductivity, optical transparency in its doped state and low bandgap. However, pEDOT has a narrow potential range of electrochemical activity and stability The increase of potential window and improvement of specific capacitance can be achieved e.g. by fabrication of organic-inorganic heterojunction with TiO2 or prussian blue analogues. Many possible applications of the hybrid require electrode polarization. Materials under applied voltage may change their crystallographic structure. Thus, we report Raman spectroscopy measurements carried out in-situ during the polarization allows to investigate changes in the structure of the obtained hybrid (H-TiO2 / pEDOT:Fehcf). Spectroelectrochemical experiments were carried out in the quartz cuvette adapted to three-compartment electrochemical cells. The measurement was carried out in the two types of solutions: aqueous (0.5 M K2SO4) and anhydrous (acetonitrile containing 0.1 M HClO4). Financial support from the National Science Center (2012/07/D/ST5/02269) is gratefully acknowledged.
Authors : Catarina R. Pedrosa, Laurent Plawinski, Marie-Christine Durrieu, Sivashankar Krishnamoorthy
Affiliations : Materials Research and Technology (MRT) Department, Luxembourg Institute of Science and Technology (LIST), 41, rue du brill, L-4408, Belvaux, Luxembourg, Institute of Chemistry & Biology of Membranes & Nanoobjects (CBMN UMR 5248, CNRS), Bordeaux University, European Institute of Chemistry & Biology, 2 Rue Robert Escarpit, 33607 Pessac, France; Institute of Chemistry & Biology of Membranes & Nanoobjects (CBMN UMR 5248, CNRS), Bordeaux University, European Institute of Chemistry & Biology, 2 Rue Robert Escarpit, 33607 Pessac, France; Institute of Chemistry & Biology of Membranes & Nanoobjects (CBMN UMR 5248, CNRS), Bordeaux University, European Institute of Chemistry & Biology, 2 Rue Robert Escarpit, 33607 Pessac, France; Materials Research and Technology (MRT) Department, Luxembourg Institute of Science and Technology (LIST), 41, rue du brill, L-4408, Belvaux, Luxembourg
Resume : Nanoscale topographies can mediate stem cell adhesion, which can consequently influence their behaviour, namely cell proliferation, differentiation and viability. By understanding the manner in which cells interact with their physical environment, it may be possible to control cellular behavior through the fabrication of substrates with unique physical properties.. Identifying the most appropriate topographic cues to engineer the cell response requires establishing robust correlations through systematic investigations. Such investigations are however complicated due to difficulty in producing nanostructure assemblies with fine-tunable geometric variables, orthogonal handles to vary one variable at a time, and realizing the assemblies on macroscopic areas of surface with minimal variability. We show the ability to create such arrays on hard (silicon or glass) as well as soft substrates (polymer) using a combination of block copolymer self-assembly and nanoimprint lithography. Our approaches deliver ability to orthogonally vary each dimension of the array (height, width, and spacing) in steps that are < 5% of the mean value. The patterns are shown attained on full wafers, with variability <10% in geometry, with feature width and spacing down to 50 nm.
Authors : L. Ondic, M. Varga., K. Hruska, A. Kromka, I. Pelant
Affiliations : The Institute of Physics, Academy of Sciences of the Czech Republic
Resume : Two-dimensional (2D) photonic crystals are photonic structures with many possible applications in optics and photonics. For example, these periodic structures prepared on dielectric materials can be used to control the propagation of light on a nanometer scale. We fabricated 2D photonic crystals on polycrystalline diamond thin layers deposited on silica substrate and studied their influence on room-temperature photoluminescence (PL) of diamond optical centers. Polycrystaline diamond composed of diamond grains has naturally many defects which leads to the fact the PL of our structures is spectrally very broad and covers the whole visible spectral range. We have shown that by employing photonic crystals, the extraction of the PL can be more than 7 times enhanced due to light coupling into leaky modes . Next, we intentionally incorporated high dose of SiV centers into our diamond layers. These are diamond optical centers with very narrow luminescence peak, also at room temperature. We will show our first results on the influence of the photonic crystals on this luminescence. This work was supported by the GACR project No. 16-09692Y.  L. Ondic et al., Scientific Reports 2, 914 (2012).
Authors : N. Spotti,1 G. Casetta,1 J. Mohanraj,1 Vanni Lughi,1 Alessandro Fraleoni-Morgera1,2,3*
Affiliations : 1: Flextronics Laboratory, Dept. of Engineering and Architecture, Univ. of Trieste, Trieste, Italy. 2: Organic OptoElectronics Laboratory, Elettra Sincrotrone Trieste, Basovizza (TS), Italy 3: CNR Nano S3, Modena, Italy
Resume : Perovskite-based PV has received a lot of interest lately due to high reported efficiencies, exceeding 20%, in easily fabricated laboratory devices [W. S. Yang et al., Science, 2015, 348, 1234]. Among the many different fabrication methods available the Vacuum Assisted Solution Process (VASP) [H. Zhou et al., MRS Bull., 2015, 40, 667] provides a convenient route to obtain effective devices. In VASP the wet processing deposition of a first inorganic layer, usually PbI, is coupled to the vacuum deposition of a halorganic derivative, usually Methyl Ammonium Iodide (MAI). Here we report over the use and optimization of the VASP procedure to create almost pinhole-free perovskitic layers, with negligible residual pristine PbI content and very good optical absorbance values, extremely promising for practical applications of these layers in PV cells.
Authors : R.A. Puglisi, C. Bongiorno, K. Brassat, C. Garozzo, A. La Magna, J.K.N. Lindner
Affiliations : University of Paderborn, Department of Physics – Nanostructuring, Nanoanalysis, and Photonic Materials, Paderborn, Germany; Center for Optoelectronics and Photonics Paderborn CeOPP, Paderborn, Germany; Consiglio Nazionale delle Ricerche, Instituto per la Microelettronica e Microsistemi, Catania, Italy
Resume : Nanoparticles of Au play an important role in the functionalization of surfaces. For many applications it is essential to control and fix the arrangement of these particles at specific sites on the surface. Recently we observed that using a simple doctor blade technique it is possible to assemble colloidal Au nanoparticles selectively in hexagonally self-arranged arrays of ~ 20 nm diameter pores in a thin SiO2 film on silicon, the pores being fabricated by PS-b-PMMA block-copolymer lithography and reactive ion etching. Surprisingly the doctor blade technique works with very diluted suspensions in which Au nanoparticles are stable against agglomeration and leads to fractions of up to 88% of pores filled with Au. The Au nanoparticle deposition mechanism is complicated by the fact that the nanoparticles used are covered by a citrate shell originating from their wet chemical fabrication method. In order to study the deposition process in more detail, cross-sectional high-resolution (scanning) transmission electron microscopy ((S)TEM) investigations were performed in order to reveal the exact size and shape of the SiO2 pores, their extension into the Si substrate and the attachment of Au nanoparticles to the walls of pores. The chemical composition of the pores filled with Au/citrate core/shell nanoparticles was mapped using STEM-EELS (electron energy loss spectroscopy). The observations largely contribute to a better understanding of the pore filling mechanism.
Authors : Katharina Brassat, Arne A. Ruediger, Julius Bürger, Wolfgang Bremser, Oliver I. Strube, Jörg K. N. Lindner
Affiliations : University of Paderborn, Department of Physics – Nanostructuring, Nanoanalysis, and Photonic Materials, Paderborn, Germany; Center for Optoelectronics and Photonics Paderborn CeOPP, Paderborn, Germany; University of Paderborn, Department of Chemistry – Biobased and Bioinspired Materials, Paderborn, Germany; University of Paderborn, Department of Chemistry – Coatings, Materials, and Polymers, Paderborn, Germany
Resume : A novel approach for bioinspired material design on prepatterned surfaces is presented. Our method combines the advantages of nanosphere lithography (NSL) and enzyme mediated autodeposition (EMA). By NSL large-area nanoparticle arrays can be obtained on a big variety of surfaces at low cost. For this, hexagonally arranged monolayers of polymer spheres are produced by convective self-assembly and act as shadow mask in a subsequent metal deposition process. In this work plasma induced shrinking of polymer spheres enables the formation of antidot structured Pt thin films on SiO2. Immobilization of the enzyme chymosin in freely accessible SiO2 areas of antidots allows to induce site-specific deposition of casein particles in the nanometer scale. Enzyme-catalyzed cleavage reactions can drastically change the solubility of dispersed biomolecules, such as casein. EMA uses this for a controlled deposition of destabilized particles in close proximity to a surface. Key factor is the tethering of enzyme onto the surface, defining the area with enzymatic activity. Limitation of enzyme activity to this reaction zone induces controlled deposition only in this area and prevents uncontrolled protein precipitation. Size of the reaction zone can be tailored and is defined in this combined approach in all dimensions. Its lateral area is determined by NSL-formed antidots, its vertical range by enzyme coupling. Site-specific deposition of protein particles was verified by XPS and AFM measurements.
Authors : Katharina Brassat, Julius Bürger, Melanie Reinecke, Dennis Briese, Kristina Duschik, Mirko Schaper, Jörg K. N. Lindner
Affiliations : University of Paderborn, Department of Physics – Nanostructuring, Nanoanalysis, and Photonic Materials, Paderborn, Germany; Center for Optoelectronics and Photonics Paderborn CeOPP, Paderborn, Germany; University of Paderborn, Department of Mechanical Engineering – Lehrstuhl für Werkstoffkunde, Paderborn, Germany
Resume : Microcontact printing using polydimethylsiloxane (PDMS) stamps is a well-known soft lithography technique to replicate nanoscale surface patterns in a most economic and efficient way. In the present contribution, nanosphere lithography masks with 618 nm diameter polystyrene spheres are used to fabricate PDMS stamps by casting PDMS on hexagonally close-packed monolayers of spheres, thermal curing and subsequent release of the stamp. Particular attention must be placed on the stamp release in order to avoid attachment of spheres to the stamp. Scanning electron and atomic force microscopy (SEM and AFM) are used to characterize the stamps, consisting of hexagonal arrays of PDMS tips. A hexane based ink of CsPbBr3 nanoparticles is used to study both the microcontact printing process of these stamps and the self-arrangement of semiconducting nanoparticles. To this end, CsPbBr3 nanoparticles are synthesized by a wet chemical procedure. Cesium lead halides are semiconductors with direct band gaps in the visible range, presently exhibiting enormous interest as a new solar cell material. The inks are characterized by photoluminescence spectroscopy and transmission electron microscopy, along with energy dispersive X-ray analysis. The perovskitic lattice structure of the observed nanoparticles and nanowires is examined by electron diffraction. For the investigation of printed patterns SEM and AFM are used.
Authors : M. A. Osman
Affiliations : Physics Department, Faculty of Science, Assiut University, Assiut 71516 E-mail: email@example.com Tel. number: 0020882412309 - 00201119158899 Fax number: 0020882080209
Resume : In this paper, we conduct a first trial study of size-dependent structural phase transition and morphological changes via thermal annealing of EDTA capped Zn0.78Cd0.22S nanoparticles (NPs). In addition, we focused our attention on the interrelation between these changes and photoluminescence (PL) and optical absorption behavior of annealed and UV irradiated samples synthesized by chemical precipitation method at ambient temperature with a crystallite size (DSch.) ≈ 2 nm. The samples were characterized using XRD, FTIR, Raman and XRF spectra, and HRTEM. It was found that increasing annealing temperature (Ta), results in structural phase transition from cubic to mixed hexagonal structures of ZnO and CdO due to size driven phase transition caused by sintering and grain growth via annealing process in air. This accompanied by the increase in the particle size and red shift of the optical band gap (Eg). Normalized PL spectrum of as-prepared nanopowder at excitation wavelength 325 nm reveals UV emission bands at 362 and 394 nm and blue emission bands at 443 nm. At Ta up to 500 ºC, no noticeable change in the PL intensity was observed; meanwhile further increase in Ta results in an enhancement of PL intensity associated with the evolution of new green emission band. PL of Zn0.78Cd0.22S NPs colloidal solution reveals emission bands at 370, 403, 453, 489, 537 and 575 nm. To explain the mechanism of PL emission of as-prepared nanopowder and colloidal solution, trapping, and recombination levels have been identified and the corresponding energy band diagrams were suggested. It was noticed that UV irradiation of colloidal solution leads to a decrease in both particle size and Urbach's tail state width accompanied by the increase of Eg, and enhancement in PL intensity. The overall enhancement in PL intensity was explained in terms of quantum size effect as a result of the reduction in the particle size by photo-corrosion, surface modification by photopolymerization, the formation of photo-passivated layers and oxygen adsorption on Zn0.78Cd0.22S nanoparticles surface.
Authors : Federico Ferrarese Lupi 1,2 , Tommaso Jacopo Giammaria 1 , Gabriele Seguini 1 , Pavo Dubček 3 , Branko Pivac 3 , Sigrid Bernstorff 4 , Michele Perego 1
Affiliations : 1) Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate Brianza, Italy 2) Nanoscience and Materials Division, Istituto Nazionale Ricerca Metrologica, Strada delle Cacce 91, 10135 Torino, Italy 3) Institut Ruđer Bošković, Bijenička cesta 54, 10000 Zagreb, Croatia 4) Elettra-Sincrotrone Trieste, SS 14, Km 163.5, in AREA Science Park, 34149 Basovizza (TS), Italy
Resume : The growing interest that the Block Copolymers (BCPs) as a versatile tool capable to generate well ordered structures at sub-20 nm scale, has pushed the need for a clear understanding of the dynamics of the self-assembly (SA) process. While there is a wide literature concerning the characterization of the in depth morphology in BCP films having a thickness (h) comparable to the characteristic dimensions of the nanometric domains (i.e. center to center distance L0 and diameter d), only few works are devoted to the accurate characterization of thicker films (h >> L0). However, the control over the orientation and long range ordering of the nano-domains in thick BCP films is mandatory for many practical applications In this work, the morphological evolution of cylinder forming poly(styrene)-b-poly(methyl methacrylate) (PS-b-PMMA) BCPs thick films treated in the Rapid Thermal Processing (RTP) machine was monitored by means of in-depth Grazing Incidence Small Angle X-ray Spectroscopy (GISAXS). The use of this non-disruptive technique allowed revealing the complexity of the formation of buried layers composed by both parallel and perpendicular oriented cylinders as a function of the film thickness (24 nm ≤ h ≤ 840 nm) and annealing time (0 s ≤ t ≤ 900 s). In these experimental conditions several differences are observed between the SA process obtained by RTP tool respect to the samples annealed in furnaces or hotplates.
Authors : M. Dialameh 1&2 , F. Ferrarese Lupi 1, D. Martella 3, G. Seguini 3, M. Perego 3, N. De Leo 1, L. Boarino 1
Affiliations : 1 Istituto Nazionale di Ricerca Metrologia (INRIM), strada delle Cacce 91, 10135 Turin, Italy 2 Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129, Turin, Italy 3 Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate Brianza, Italy
Resume : In this work we investigated the possibility to fabricate holey Ge membranes through self-assembly of asymmetric polystyrene-b-poly (methylmethacrylate) (PS-b-PMMA) block copolymer (BCP) masks with different molecular weight (in a range between Mn = 54 Kg/mol and 82 Kg/mol). The self-assembly process has been obtained in the rapid thermal processing (RTP) machine. Two different approaches have been explored, concerning the use of a hard mask of SiO2 and a soft mask of PS. In the case of the hard mask, 5 nm of SiO2 were deposited by e-beam evaporation of over the Ge layer. Afterwards the BCP mask has been prepared over the SiO2 layer and the nanometric pattern was transferred into the SiO2 with a mixing mode of CHF3/Ar gases. On the other hand the soft mask fabrication was accomplished after selective removal of PMMA cylinders and removal of P(S-r-MMA) random copolymer directly from bottom of opened cylinders. A systematic analysis of the grafting process of RCP on Ge has been also performed in order to obtain perpendicular aligned cylinders. In both the aforementioned cases, the pattern transfer into the Ge was performed by means of a reactive ion etching (CCP RIE) using CF4/O2 gases. As result of this study holey Ge membranes having variable pore diameter (between 10 nm and 25 nm) and etched depth (from 5 to 30 nm) were obtained. Acknowledgment: This work has been done under framework of 3DMetChemIT project (EMPIR project 14IND01).
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Doping of Nanostructures : Seguini G.
Authors : Roie Yerushalmi
Affiliations : Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Edmond J Safra Campus, Givat Ram Jerusalem, 91904, Israel.
Resume : Monolayer doping (MLD) and monolayer contact doping (MLCD) offers a substantial advancement toward the controlled, ex-situ doping of nanowires using molecular monolayers as dopant source with uniform, self-limiting characteristics that is applied to the nanostructures post-synthesis and decoupled from the synthesis step. Accordingly, monolayer doping methods draw significant attention in recent years as evident by the vibrant activity in the field. The ability to form well controlled doping profiles at the nanoscale is especially appealing in the context of photovoltaic and photocatalysis. Developing a process which allows the formation of well-controlled, heterogeneous, and registered doping profiles in nanostructures without the application of high resolution lithographic methods pose a significant challenge to-date. This is because the combined requirements of symmetry breaking, control of chemical composition and registry at the nanoscale pose a significant challenge. In my talk I will present recent results obtained by a new monolayer doping methods developed in our group.
Authors : S. Caccamo, A. La Magna and R.A. Puglisi*
Affiliations : Consiglio Nazionale delle Ricerche - Istituto per la Microelettronica e Microsistemi, Strada Ottava 5, Z.I 95121. Catania, Italy
Resume : Nowadays with the modern developments in the semiconductor device technologies, conventional doping process has shown its limits such as high costs of equipments and their maintenance, crystal damage and necessity of multiple processing steps to achieve conformality. The last two drawbacks manifested especially in applications requiring 3D nanostructured Si surfaces. In 2008 a low cost technique for nanoscale controlled doping of semiconductors was reported [Ho et al., Nat. Nanomat. 7, (2008) 62]. It consists in the monolayer formation during the immersion of the sample in a chemical bath containing dopant precursors molecules and successive thermal treatment to diffuse the dopant. In order to understand the contribution of the surface doped layer on the electrical properties a new method, the chemical four point probe (C-4PP), has been developed. It consists in the repeated removal of thin layers of surface doped Si by using wet etches and successive 4PP measurements. Here we present a study of the oxide cap-layer effects on the migration of the carbon atoms constituting the precursor molecules. Two phenomena have been considered: the evaporation and the chemical bonding with the Si substrate. The measurements have been performed by X-ray spectroscopy analysis and C-4PP.
Authors : Michele Perego (a), Massimo Mastromatteo (b), Davide De Salvador (b), Enrico Napolitani (b), Elisa Arduca (a,c), Gabriele Seguini (a), Jacopo Frascaroli (a), Giuseppe Nicotra (d), Corrado Spinella (d) and Alberto Carnera (b)
Affiliations : (a) Laboratorio MDM, IMM-CNR, Via Olivetti 2, I-20864 Agrate Brianza, Italy (b) Dipartimento di Fisica e Astronomia, Universita` degli Studi di Padova and CNR-IMM MATIS, Via Marzolo 8, I-35131 Padova, Italy. (c) Dipartimento di Fisica, Universita` degli Studi di Milano, Via Celoria 23, I-20100 Milano, Italy (d) IMM-CNR, Z. I. VIII Strada 5, I-95121 Catania, Italy
Resume : Deterministic doping of nanostructures is a key challenge for the fabrication of future advanced nanoelectronic devices. Unfortunately, a clear understanding of nanoscale doping is not available yet, as the physical mechanisms involved in this process are significantly different from those of bulk materials, due to additional constrains related to the presence of the interfaces and of the surrounding oxide matrix. In this regard, Si NCs embedded in a SiO2 matrix represent a paradigmatic system for the physical understanding of dopant incorporation in Si-based nanostructures. In this work the thermodynamic stability of P dopant impurities in Si nanocrystals at thermodynamic equilibrium is investigated. To achieve this goal samples with controlled diffusion sources that are spatially separated from the nanocrystals were fabricated and a controlled amount of dopant atoms from the dopant source was delivered to the nanocrystals by diffusing the dopants trough the SiO2 matrix. A simple model based on diffusion Fick’s law in one dimension was used to determine the energy barriers (1 eV) for P trapping/de-trapping at the SiO2/Si NCs interface, obtaining a complete picture of the system at equilibrium. The trapping efficiency was investigated as a function of the nanocrystal size.
Authors : K. Sparnacci
Affiliations : 1. Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Università del Piemonte Orientale ‘‘A. Avogadro’’, Viale T. Michel 11, 15121 Alessandria, Italy
Resume : The capability to control dopant incorporation within semiconductor materials with atomic accuracy represents a major challenge toward further scaling of electronic devices. A promising strategy is the monolayer doping (MLD), which consists in the creation of a well-ordered monolayer of dopant-containing molecules bonded to the surface of the substrate. In this work, we extended this approach by studying phosphorous (P) monolayer doping formation on SiO2 substrates through the “grafting to” of dopant-containing end-functional polymers. As the “grafting to” is a self limiting reaction, it is straightforward to produce a grafted layer featuring homogeneous thickness on a large area. In addition, the limiting thickness and the grafting density and consequently the phosphorous surface density, are controlled by the molar mass of the employed end-functional polymer. In more detail, two series of polystyrene and polymethylmethacrylate phosphate-terminated were prepared with molar masses ranging from 1500 to 20000 g/mol and narrow polydispersity indexes. These polymers were grafted to an activated silica surface by thermal annealing in a Rapid Thermal Processing (RTP) apparatus at 250°C for time periods ranging from few seconds to several minutes. Subsequent removal of the organic layer by oxygen plasma and capping with SiO2 leads to the formation of a P δ-layer embedded in a SiO2 matrix and spatially separated from the Si substrate. The amount of phosphorous bounded to the surface was determined by means of Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS). By varying the molecular weight of the dopant-terminated polymer the control the final density of the dopant atoms was demonstrated.
Nanostructures: Synthesis and Applications I : Ben-Assayag G.
Authors : S. Godlewski,1 M. Kolmer,1 M. Engelund,2 H. Kawai,3 R. Zuzak,1 A. Garcia-Lekue,4 A. M. Echavarren,5 D. Pena,6 D. Perez,6 E. Guitian,6 C. Joachim,7 D. Sanchez-Portal,2,4 M. Saeys,8 M. Szymonski1
Affiliations : 1 Department of Physics of Nanostructures and Nanotechnology, Institute of Physics, Jagiellonian University, Łojasiewicza 11, PL 30-348, Krakow, Poland 2 Centro de Fisica de Materiales CSIC-UPV/EHU, Paseo Manual de Lardizabal 5, 20018, Donostia-San Sebastian, Spain 3 Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602, Singapore 4Donostia International Physics Center, Paseo Manual de Lardizabal 4, 20018, Donostia-San Sebastian, Spain 5 Institute of Chemical Research of Catalonia (ICIQ), Avenida Països Catalans 16, 43007 Tarragona, Spain 6 Centro de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidad de Santiago de Compostela, Santiago de Compostela 15782, Spain 7 Nanosciences Group & MANA Satellite, CEMES-CNRS, 29 rue Jeanne Marvig, F-31055 Toulouse, France 8 Ghent University, Laboratory for Chemical Technology, Technologiepark 914, B-9052 Gent, Belgium
Resume : The controlled formation and breaking of chemical bonds between organic molecules and single atoms attracts recently growing attention inspired by the interest in the fundamental knowledge of elementary processes occurring between the molecules and atoms. In particular, the controlled and reversible bonding between single molecules and atoms could be advantageous in construction of prototypical molecular switches, rotors and electronic circuits. In many applications the retention of originally designed electronic properties of polyaromatic platforms is crucial. It is expected that the problem of strong coupling of the electronic structure of the molecule with the metallic substrate could be resolved by application of passivated surfaces [1-3]. Among them, the hydrogenated semiconductors attract considerable interest due to possibility to create atomically precise artificial wiring comprised of surface dangling bonds [4-5]. Here we will characterize behavior of 3-input trinaphthylene and tris(biphenylene) molecules on the hydrogenated Ge(001):H substrate with the application of low temperature scanning tunneling microscopy/spectroscopy (STM/STS) supported by the advanced theoretical modeling. We will show that the molecules initially undergo a Diels-Alder [4+2] cycloaddition to paired surface dangling bonds . It will be shown that with the application of the STM tip these chemical bonds could be reversibly formed and broken. Moreover, for the first time we will discuss the fabrication of a molecular rotor with a dangling bond bearing that could be operated by vibronic excitations with tunneling electrons. Further, it will be shown that by tuning the structure of the molecules the Diels-Alder attachment geometry could be controlled with high selectivity. Finally we will introduce prospects for utilization of the control over connecting individual molecules with surface single atoms.  Szymon Godlewski, Marek Kolmer, Hiroyo Kawai, Rafal Zuzak, Bartosz Such, Mark Saeys, Paula de Mendoza, Antonio M. Echavarren, Christian Joachim, Marek Szymonski, ACS Nano 7 (2013) 10105–10111  Amandine Bellec, Francisco Ample, Damien Riedel, Gerald Dujardin, Christian Joachim, Nano Lett. 9 (2009) 144–147.  Szymon Godlewski, Marek Kolmer, Mads Engelund, Hiroyo Kawai, Rafal Zuzak, Aran Garcia-Lekue, Mark Saeys, Antonio M. Echavarren, Christian Joachim, Daniel Sanchez-Portal and Marek Szymonski, Phys. Chem. Chem. Phys. 18 (2016) 3854  Marek Kolmer, Szymon Godlewski, Hiroyo Kawai, Bartosz Such, Franciszek Krok, Mark Saeys, Christian Joachim, Marek Szymonski, Phys. Rev. B 86, 125307 (2012)  Marek Kolmer, Rafal Zuzak, Ghassen Dridi, Szymon Godlewski, Christian Joachim and Marek Szymonski, Nanoscale 7 (2015) 12325  Szymon Godlewski, Hiroyo Kawai, Mads Engelund, Marek Kolmer, Rafal Zuzak, Aran Garcia-Lekue, Gerard Novell-Leruth, Antonio M. Echavarren, Daniel Sanchez-Portal, Christian Joachim, Mark Saeys, Phys. Chem. Chem. Phys. 2016, DOI: 10.1039/C6CP02346K This research was supported by the National Science Centre, Poland (contract no. UMO-2014/15/D/ST3/02975) and the 7th Framework Programme of the European Union Collaborative Project PAMS (contract no.610446).
Authors : Guillem Domènech-Gil (1), Jordi Samà (1), Paolo Pelegrino (1), Sven Barth (2), Albert Romano-Rodriguez (1)
Affiliations : 1. Universitat de Barcelona (UB), MIND-Department d’Enginyeria and Institute of Nanoscience and Nanotechnology (IN2UB), E-08028 Barcelona, Spain 2. Vienna University of Technology (TUW), Institut für Materialchemie, A-1040 Vienna, Austria
Resume : Gallium and indium oxide nanomaterials have been fabricated via carbothermal reduction using a chemical vapor deposition (CVD) method and employing gallium and indium oxide nanopowder mixed with graphite as source material. The growth has been carried out under flow of argon or argon mixed with oxygen. The resulting materials have been structurally and optically characterised using X-ray diffraction, scanning and transmission electron microscopy and related techniques, as well as photoluminescence and Raman spectroscopy, confirming their crystalline nature. To study the gas sensing properties, the nanowires were removed from the substrates applying sonication, followed by the deposition on suspended micro-hot-plates with pre-patterned electrodes and individual nanomaterials were contacted by combined Focused Electron- and Focused Ion-Beam assisted deposition techniques, as well as evaporated contacts defined by Electron Beam Lithography. The fabricated devices have been successfully tested towards several gases relevant in air quality control, such as NO2 and CO, at different concentrations and temperatures in a self-made test chamber.
Authors : Yuxue Cai, Hauke Lehmann, Svenja Willing, Sandra Möller, Mirjam Volkmann, Christian Klinke
Affiliations : University of Hamburg, Institute of Physical Chemistry, Grindelallee 117, 20146 Hamburg, Germany
Resume : Colloidal chemistry allows synthesizing monodisperse particles with diameters of only a few nanometers. Such structures possess a tiny electrical capacity. In transport measurements this results in the phenomenon of Coulomb blockade. Characteristic current oscillations have been observed in devices comprising individual nanoparticles (e.g. Andres et al., Science 272 (1996) 1323; Klein et al., Appl. Phys. Lett. 68 (1996) 2574). In my talk, I will demonstrate that by means of a gate voltage current modulations can be observed also in extended, monolayered films - realizing transistor function. The nanocrystal assembly by the Langmuir-Blodgett method yields super-crystalline, monolayered films over vast areas. A dielectric oxide layer protects the metal nanocrystal field-effect transistors from oxidation and leads to stable function for months. Comprehensive electrical measurements allow determining the reigning charge transport mechanisms. Such devices could be a new approach for low-cost electronic applications based on a new principle. References: * Yuxue Cai, Jan Michels, Julien Bachmann, Christian Klinke: Metal nanoparticle field-effect transistor, J. Appl. Phys. 114 (2013) 034311. * Hauke Lehmann, Svenja Willing, Sandra Möller, Mirjam Volkmann, Christian Klinke: Coulomb blockade based field-effect transistors exploiting stripe-shaped channel geometries of self-assembled metal nanoparticles, Nanoscale (2016) under review.
Authors : Magatte N. Gueye [1,2], Alexandre Carella , Nicolas Massonnet , Etienne Yvenou , Sophie Brenet , Jérôme Faure-Vincent , Stéphanie Pouget , François Rieutord , Hanako Okuno , Anass Benayad , Renaud Demadrille  and Jean-Pierre Simonato .
Affiliations :  University Grenoble Alpes, CEA/LITEN, F-38054 Grenoble, France.  University Grenoble Alpes, CEA, INAC, CNRS, INAC, F-38000 Grenoble, France  University Grenoble Alpes, INAC-MEM, F-38000 Grenoble, France.
Resume : Poly(3,4-ethylenedioxythiophene) (PEDOT) is certainly the most known and most used conductive polymer since it is commercially available and shows great potential for organic electronic, photovoltaic and thermoelectric applications. Studies dedicated to PEDOT films have led to high conductivity enhancements.  However, an exhaustive understanding of the mechanisms governing such enhancement is still lacking, hindered by the semi-crystalline nature of the material itself. We report the development of highly conductive PEDOT films by controlling the crystallization of the PEDOT chains and by a subsequent dopant engineering approach using iron (III) trifluoromethanesulfonate as oxidant, N-methyl pyrrolidone as polymerization rate controller and sulfuric acid as dopant. XRD, HRTEM, Synchrotron GIWAXS analyses and conductivity measurements down to 3 K allowed us to unravel the organization, doping and transport mechanism of these highly conductive PEDOT materials. N-methyl pyrrolidone promotes bigger crystallites and structure enhancement during polymerization while sulfuric acid treatment allows the replacement of triflate anions by hydrogenosulfate and increases the charge carrier concentration. We finally propose a charge transport model that fully corroborates our experimental observations. These polymers exhibit conductivities up to 5400 S cm-1 and transmittance at 550 nm between 80 and 96 % and thus show great promise for the replacement of ITO as transparent electrodes.  N. Massonnet, A. Carella et al, Chem. Sci. 2015, 6, 412–417  M. N. Gueye, A. Carella et al, Chem. Mater., 2016 In press
Authors : J. Samà (1), S. Barth (2), G. Domènech-Gil (1), M. Seifner (2), I. Gracia (3), C. Calaza (3), P. Pellegrino (1) and A. Romano-Rodríguez (1)
Affiliations : 1) Universitat de Barcelona (UB), MIND-Department d’Enginyeria and Institut de Nanociència i Nanotecnologia (IN2UB), 08028 Barcelona, Spain 2) Vienna University of Technology, Institute of Materials Chemistry, 1060 Vienna, Austria 3) Consejo Superior de Investigaciones Científicas (CSIC), Centre Nacional de Microelectrònica-Institut de Microelectrònica de Barcelona-, 08193 Bellaterra, Spain
Resume : In the last decade huge efforts have being put to use nanowires as building-blocks in functional electronic devices, and ease their integration to lower cost and power consumption. Their high surface-to-volume ratio, as well as well controlled physical and chemical properties are the key features towards toxic gases detection and environmental monitoring. In this work we present a novel gas sensor based on Ge nanowires. By means of a modified CVD method, its localized growth has been carried out on top of micro-membranes equipped with a buried heater, which requires a low power supply. In this way the deposition is focused right onto the sensing area, and with a negligible power budget of just few milliwatts, instead of tens –hundreds watts required by a conventional growth. We demonstrate that germanium nanowires react to the presence of both reducing and oxidizing gases acting as a chemi-resistor, similarly to metal oxide materials. Their surface is covered by a Ge oxide, whose thickness is maintained stable by working in a low temperature range. Ge NWs show a moderate response against the presence of NO2 and CO in a range of several ppm, diluted in synthetic air. Response has been observed even at room temperature, although a better yield is achieved working around 100ºC. This integrated structure provides a functional sensor with an excellent power performance under operation, of few mW for both heating and measuring.
Authors : D. Smazna, F. Schütt, J.Gröttrup, J. Carstensen, Y. K. Mishra, R. Adelung
Affiliations : Functional Nanomaterials, Institute for Materials Science, Kiel University, Kaiserstr. 2, D-214143, Kiel, Germany
Resume : The recently developed flame transport synthesis (FTS) approach by the group of Prof. Adelung has demonstrated the rapid and mass-scale production of three dimensional (3D) microstructured zinc oxide (ZnO) in various shapes ranging nanoscale one dimensional (1D) structures to nano- and microscale tetrapods or centimeter scale long wires . An overview about the FTS approach, dependence of different experimental parameters on the resultant nano- and microstructures from metal oxide semiconductors will be presented. Electronic devices based on tetrapods, nano- and microneedles and 3D porous networks, etc. have been successfully fabricated and characterized in detail. These nanostructures based devices have been utilized for various sensing purposes. The tetrapods network based nanosensing device has demonstrated interesting gas/UV sensing characteristics. Due to hexagonal-wurtzite crystal structure with non-center of symmetry, 1D structures from ZnO are quite good for piezotronics applications however this field still lacks with several issues in terms of proper nanoscale integrations and responses. Here, a piezotronic device based FTS grown ultra-long ZnO nano- and microneedle was investigated in detail and same will be presented. The FTS grown ZnO nano- and microstructures offer a possibility of their further functionalization by loading their surfaces with interesting nanostructures, e.g., gold nanoparticles or fullerenes, etc. This leads to development of hybrid 3D nanomaterials which might be interesting for many technological applications and some preliminary results from these hybrid 3D nanomaterials will be demonstrated. References:  Particle and Particle Systems Characterizations 30, 2013, 775-783.  ACS Applied Materials & Interfaces, 7, 2015, 14303–14316.  Physica Status Solidi A 2016, (DOI: 10.1002/pssa.201532924)
2D-Nanostructures : Pellegrino P.
Authors : Sang Ouk Kim
Affiliations : National Creative Research Initiative (CRI) Center for Multi-Dimensional Directed Nanoscale Assembly, Department of Materials Science & Engineering, KAIST, Daejeon 34141, Republic of Korea
Resume : Graphene based materials, such as carbon nanotubes and graphene, attract enormous research attention for their outstanding material properties along with molecular scale dimension. Optimized utilization of the graphene based materials in various applications requires the subtle controllability of their structures and properties. In this presentation, our recent research works associated to nanoscale organization and chemical modification of graphene based nanostructures will be presented. Carbon nanotubes and graphene can be efficiently organized into various three-dimensional nanostructures via self-assembly principles. The resultant carbon nanostructures with extremely large surface and high electro-conductivity are potentially useful for catalysis, energy storage and so on. Aqueous dispersion of graphene oxide shows liquid crystalline phase, whose spontaneous molecular ordering is useful for display or fiber spinning. In addition, the substitutional doping of graphitic carbon with B- or N- was achieved via pre- or post-synthetic treatment. The resultant chemically modified graphene based nanostructures with tunable workfunction and remarkably enhanced surface activity could be employed for organic solar cells, nanocomposites and dopant specific unzipping process for improved functionalities and device performances.
Authors : J.E. ten Elshof
Affiliations : MESA+ Institute for Nanotechnology, University of Twente, Enschede, the Netherlands
Resume : Metal oxide nanosheets are the oxide equivalents of graphene. They have thicknesses of 0.5 to few nm and lateral sizes up to tens of micrometers. Nanosheets are prepared by chemical exfoliation of layered metal oxides, and they can be assembled into densely packed 2D monolayer films using a Langmuir-Blodgett approach on any type of substrate, even curved or 3D patterned substrates. Since nanosheets are 2D single crystals with only one type of surface termination, they are versatile seed layers for oriented and epitaxial growth of subsequent functional metal oxide thin films. In this contribution the preparation and use of nanosheet films as seed layers for the formation of preferentially oriented nanoelectronic oxide films by pulsed laser deposition is discussed. Oriented perovskite-type SrRuO3, (La,Sr)MnO3, Pb(Zr,Ti)O3 and BiFeO3 films have been grown on Ca2Nb3O10 and Ti0.87O2 nanosheets. Depending on the nature of the seed layer, either  or  oriented films with properties depending on the orientation are formed. Moreover, the lateral sizes of the nanosheets are shown to offer an independent handle to modulate the properties of these films. Micropatterns of different nanosheets by photolithography and lift-off are demonstrated, illustrating the possibility to control the orientation of functional films even on micrometer-scale. The transfer of these films to temperature-sensitive substrates such as plastics is also discussed.
Authors : Edita Vernickaite, Oksana Bersirova, Martynas Lelis, Henrikas Cesiulis
Affiliations : Vilnius University, Vilnius, Lithuania; V.I. Vernadskii Institute of General & Inorganic Chemistry, Kiev, Ukraine; Lithuanian Energy Institute, Kaunas, Lithuania; Vilnius University, Vilnius, Lithuania.
Resume : Hydrogen evolution technology is considered as a key element for the sustainable economic growth and generation of clean future energy . Mostly platinum is applied in electro-catalytic systems for hydrogen evolution reaction (HER), and the development of new cost effective and durable materials which possess high catalytic activity for HER is necessary. The metallic Mo or its alloys can be used as active electrodes for hydrogen evolution . Electrodeposits of metallic Mo can be obtained from non-aqueous and molten salt electrolytes . Unfortunately, the pure Mo deposits cannot be obtained from aqueous molybdate solutions, but Mo easily codeposits with iron group metals (Ni, Co, Fe) . It is known that such alloys demonstrate good electro-catalytic properties towards the hydrogen evolution reaction in both acidic  and alkaline solutions . In this study Ni-Mo, Co-Mo, Fe-Mo rich in Mo alloys were electrodeposited onto copper substrates under galvanostatic mode from ammonia-acetate electrolyte. The highest amount of Mo (~ 52 at.%) was achieved at 30 mA/cm². At higher current density the content of Mo in the alloys decreases. The prepared coatings have an uniform thickness (10-30 µm), compact, dense and consisted of fine-grained crystallites. Electro-catalytic activity towards cathodic hydrogen evolution in 30 % NaOH solution in the temperature range of 25-65 °C on the electrodeposited Co-Mo, Fe-Mo and Ni-Mo alloy coatings by means of voltammetry. It was found that the exchange current densities for hydrogen evolution reaction increases with the temperature increase. The Co-Mo and Fe-Mo alloy coatings demonstrated the highest catalytic effect for hydrogen evolution reaction at 65 °C. It was determined that the exchange current density of hydrogen evolution onto Co-Mo and Fe-Mo deposits is ~ 0.45 A/cm², and it is considerably higher than that for Ni-Mo alloy coatings in the whole range of the temperatures. Acknowledgment. This study was founded from MSCA-ITN-2014-ETN No. 642642, and Research Council of Lithuania (MIP-031/2014). References  Züttel, A. Borgschulte, L. Schlapbach, Hydrogen as a future energy carrier. Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim, 2008.  N. Elezovic, B. N. Grgur, N. V. Krstajic, V. D. Jovic, J Serb Chem Soc 70 (6) (2005) 879-889.  H. Capel, P.H. Shipway, S.J. Harris, Wear 255 (2003) 917.  A. Brenner, Electrodeposition of Alloys, 2, Academic Press Inc., New York, 1963.  E. Navarro-Flores, Z. Chong, S. Omanovic, J Mol Catal A Chem 226 (2005) 179.  A. Subramania, A. R. Sathiya Priya, V. S. Muralidharan, Electrocatalytic cobalt-molybdenum alloy deposits. Int J Hydrogen Energy 32 (2007) 2843.
Authors : Sonia Metel, Andrés Seral-Ascaso, Valeria Nicolosi
Affiliations : School of Chemistry, Trinity College Dublin, Ireland; CRANN, Trinity College Dublin, Ireland; School of Physics, Trinity College Dublin, Ireland
Resume : Semiconducting materials are a large family of chemical compounds presenting unique optical, electronic and mechanical characteristics and they have many promising applications in several different research fields. Moreover, when reducing the particles size to the nanoscale, their physical and chemical properties are enhanced which might lead to the development of smaller and more effective devices that could make a valuable contribution and revolutionize semiconductors industry. Different synthesis methods have been used to obtain semiconducting nanoparticles with certain geometrical attributes. In spite of the large number of possibilities, due to its high costs and complexity they are not most of the times applicable in industry. Therefore, there is an urgent need to develop simple and affordable methods to allow industrial scale fabrication of these nanomaterials. Regarding this, special attention has been placed on wet-chemistry methods, which have shown their great potential for the preparation of nanostructures with controlled shape and size. Wet chemistry synthesis based on long-chain amines are particularly interesting due to amines multiple role: as a solvent, surfactant and mild reducing agent. Their use in synthesis of 1D nanostructures has been previously described for several semiconducting compounds, while gallium/chalcogens structures have never been studied. In the presented work the synthesis of gallium sulphide and gallium selenide nanotubes in a mixture of hexadecylamine and dodecylamine is reported. It was found that the amines are homogenously intercalated within the nanotubes structure. Their optical properties make them promising for electro-optical applications.
Authors : Debosmita Karar, Mallar Ray
Affiliations : Dr. M.N. Dastur School of Materials Science and Engineering, Indian Institute of Engineering Science and Technology,Shibpur, (Formerly Bengal Engineering and Science University,Shibpur.) Howrah-711103 West Bengal,India.
Resume : Unlike graphene, development of 2D Si, often referred to as silicene, is overwhelmingly difficult due to the dominant sp3 hybridization in Si. Nevertheless, very much like graphene, 2D Si is expected to have exotic properties along with the advantage of being readily interfaced with the existing Si technology. In this work we demonstrate the development of quasi 2D sheets of crystalline Si by wet chemical exfoliation of layered silicide material (CaSi2). Samples have been formed as powder as well as colloidal dispersions in a variety of solvents. Development of nanocrystalline Si is evidenced from the distinct but broadened peaks of Si observed in x-ray diffraction (XRD) pattern. Flake like structures with lateral spread in the micrometer range and thickness of few nanometers are confirmed by electron and atomic-force microscopy. Electron diffraction studies also bear clear indication of nanostructuring along with crystalline features of Si. Colloidal suspension of the as-prepared quasi 2D flakes of Si exhibit bluish green luminescence under UV excitation that is detectable with the unaided eye. Spectroscopic signatures reveal that along with Si, oxide, hydride and hydroxide species are also present, which passivate the surface dangling bonds. However, the absorption and emission spectral characteristics of the sample are very different from bulk siloxene. The developed material serves as an excellent precursor for obtaining truly 2D silicene with tunable surface termination.
Optical and Plasmonic Applications I : Perego M.
Authors : David J. Norris
Affiliations : ETH Zurich
Resume : Quantum optics involves the coupling of quantum emitters to their electromagnetic environment. Because this coupling is related to the concentration of the optical field, it is typically constrained by the diffraction limit of light. One way to circumvent this is by moving to quantum plasmonics, which uses surface plasmon polaritons (SPPs) instead of photons. However, despite the advantages of this approach, quantum plasmonics has not yet been fully explored. It has been limited in large part by experimental difficulties in creating the necessary structures. We address this problem by combining state-of-the-art quantum emitters with plasmonic structures (waveguides and reflectors) that approach theoretical performance limits. We synthesize highly luminescent colloidal quantum dots (photoluminescence quantum yield >90%) and precisely place them on template-stripped silver surfaces. By proper design of such surfaces, high-quality plasmonic waveguides can be obtained. We demonstrate efficient coupling of the quantum-dot emission into guided plasmonic modes of such waveguides. In addition, by adding efficient reflectors, high-Q plasmonic resonators are created. More generally, the flexibility and fidelity of the resulting quantum-plasmonic systems indicates that they will allow a broad set of nanoscale quantum-optical measurements to be pursued.
Authors : C. Mennucci 1, G. Della Valle 2, M.C. Giordano 1, D. Repetto 1, and F. Buatier de Mongeot 1
Affiliations : 1 Department of Physics, University of Genova, Via Dodecaneso 33, I-16146, Genova, Italy 2 Department of Physics, Politecnico di Milano, P.zza Leonardo da Vinci 32, I-20133 Milano, Italy ?
Resume : Self-organized arrays of plasmonic nanostructures are confined on nanopatterned templates over large cm^2 areas. Highly ordered Au nanowire(NW) arrays are confined, by glancing angle deposition, on rippled glass templates prepared by direct Ion Beam Sputtering[1,2]. Steep faceted ripples with subwavelegth periodicity and length in the range of several microns drive the growth of tilted Au NWs endowed with dichroic optical response. For transversal light polarization Au NWs support a sharp Localized Plasmon resonance, easily tunable into the VIS spectrum by tailoring the NWs morphology, whereas the resonance is deeply shifted in the IR for longitudinal polarization. Furthermore, we investigate the feasibility of template assisted fabrication of Au NW dimers, in the form of tilted Au-silica-Au nanosandwiches. These kind of structures, also referred to as gap plasmonic nanostructures, have the potential to exhibit a high-Q magnetic-dipole plasmonic resonance, characterized by a strong near field confinement. Alternatively, two-dimensional arrays of plasmonic nanocrescents are confined on self-assembled monolayer of polymeric nanospheres , optimizing their efficiency as optical nanoantennas in SERS. References Giordano M.C. et al. "Template assisted growth of transparent plasmonic nanowire electrodes" submitted to Nanotechnology. Belardini A. et al. Phys.Rev.Lett. 257401, 2011. Robbiano V. et al. Adv.Opt.Mater.1,389, 2013. Giordano M.C. et al. ACS Appl.Mater.Interf. 8,6629, 2016.
Authors : A. Cabos, C. Celle, B. Laguitton, J-P. Simonato
Affiliations : CEA-LITEN / DTNM / SEN / LSIN
Resume : Abstract: Transparent conductive thin films are widely used in technologies such as solar cells, light-emitting diodes, and displays. The fabrication of these films is currently realized with thin films of transparent conductive oxides (TCOs), and in particular indium tin oxide (ITO). The as-made ITO transparent conductors suffer from limitations like costly fabrication process and brittleness. The use of solution-processable nanomaterials, and especially metallic nanowires, appears to be a promising alternative. Indeed it affords a large random two dimensional nanowire area, and low-cost deposition method with high performances . Among metals, silver is the more mature process, copper has merely the same properties, with other advantages: price and abundance. Thanks to polyol (or hydrothermal for copper) process, metallic nanowires are synthesized in our laboratory. Silver nanowires have a mean length of 10 µm and a mean diameter of 60 nm whereas copper nanowires have a mean length of 54 µm and a mean diameter of 53 nm . Their dimension confers them a high aspect ratio. Randomly dispersed on a substrate, at the percolation threshold, metallic nanowires lead to high performance, transparent and flexible electrodes. Many printing techniques are available to produce those electrodes in order to integrate them into devices such as thermal film heaters, thermochromic displays or touch sensors  . Thanks to the use of spray coating, nanowire electrodes have excellent performance (i.e. R□<20Ω/□ at T>90%) . Moreover stability of silver nanowire electrodes under ambient air is very promising since sheet resistance of electrodes is suitable with devices after four years of ageing. Stability of copper nanowire electrodes in air is shorter since sheet resistance is stable approximately for three months. The study will be focused on stability of electrodes under various stresses (electrical and environmental). More details will be given on stability of those electrodes in operating conditions and their reaction at different stresses. Part of the study will also deal with other nanomaterials synthesis, in particular core-shell nanowire synthesis. The purpose is to protect copper nanowires with a metallic shell to improve stability of the corresponding electrodes. Finally performance and stability under different environments of core-shell nanowire electrodes are studied and compared with copper and silver nanowire electrodes. Keywords: Organic, flexible and printed electronics / metallic nanowire/ transparent electrode References:  D. Langley, G.Giusti, C. Mayousse, C. Celle, D. Bellet, J.-P. Simonato, Nanotechnology, 24, 452001 (2013)  C. Mayousse, C. Celle, A. Carella , J.-P. Simonato, Nano Research, 7(3) : 315-324 (2014)  Celle, C., Mayousse, C., Moreau, E., Basti, H., Carella, A., & Simonato, J.-P. Nano Research, 5(6), 427–433. (2012)  Mayousse, C., Celle, C., Moreau, E., Mainguet, J.-F.
Authors : M. A. Osman1,*, A. G. Abd-Elrahim1, A. A. Othman1, Waleed A. El-said2
Affiliations : 1 Physics Department, Faculty of Science, Assiut University, Assiut 71515, Egypt 2 Chemistry Department, Faculty of Science, Assiut University, Assiut 71515, Egypt
Resume : In this paper, we conduct a first trial study of size-dependent structural phase transition and morphological changes via thermal annealing of EDTA capped Zn0.45Cd0.55S nanoparticles (NPs) synthesized by chemical precipitation method with a crystallite size (DSch.) ≈ 2 nm. In addition, we focused on the interrelation between these changes and photoluminescence (PL) and optical absorption behavior of annealed and UV irradiated samples. The samples were characterized using XRF, XRD, FTIR, Raman, and UV-vis spectroscopy and HRTEM. It was found that increasing annealing temperature (Ta), results in structural phase transition from cubic to hexagonal structure at 400 oC due to size driven phase transition caused by sintering and grain growth accompanied by increase in the particle size and red shift of the optical band gap ("E" _"g" ^"opt" ). Normalized PL spectrum of Zn0.45Cd0.55S nanopowder at excitation wavelength 325 nm reveals new UV emission bands at 353 and 372 nm and blue emission bands at 406 and 468 nm. With increasing Ta up to 500ºC the PL intensity was quenched and red shifted. On the other hand, a colloidal solution of Zn0.45Cd0.55S NPs reveals emission bands at 388, 460, 504, 557 and 605 nm. To explain the mechanism of PL emission of the colloidal and powder Zn0.45Cd0.55S nanoparticles, trapping and recombination levels have been identified and the corresponding energy band diagrams were suggested. It was noticed that, UV irradiation of Zn0.45Cd0.55S colloidal solution leads to a decrease in the particle size and Urbach's tail state width accompanied by blue shift of Egopt, and enhancement in PL intensity. The overall enhancement in PL intensity was explained in terms of quantum size effect as a result of the reduction in the particle size by photocorrosion, surface modification by photopolymerization, formation of ZnSO4 and CdSO4 passivation layers and oxygen adsorption on Zn0.45Cd0.55S nanoparticles surface.
Authors : Chayanika Josh, Madhumita Choudhuri, Alokmay Datta, Mallar Ray
Affiliations : Dr. M. N. Dastur School of Materials Science and Engineering, Indian Institute of Engineering Sciences and Technology, Shibpur; Saha Institute of Nuclear Physics,Bidhan Nagar, Kolkata.
Resume : Although self assembly (SA) is a very common natural phenomenon that has been utilized in organic thin film synthesis, very few works have so far been done on SA of semiconductor nanostructures. Here we demonstrate formation of a thin film of luminescent nanocrystalline silicon by SA on air water interface. Silicon nanocrystals were prepared by a simple mechano-chemical technique and were subsequently functionalized by amphiphilic fatty acid. The film floating on air-water interface exhibit intense luminescence and can be viewed with the naked eye. Langmuir-Blodgett (LB) films of the functionalized silicon nanocrystals were formed on solid substrates by simple lift-off in an LB trough. Structural features were investigated using transmission electron microscopy (TEM) and electron diffraction which reveal nanocrystalline silicon with very small sizes in the range of 2-10 nm. Brewster angle microscopy (BAM) images provide strong evidence for formation of nearly monolayer of capped silicon nanocrystals film. We have observed the pressure versus area isotherms of the films in LB trough and tracked the hysteresis tendency. Spectroscopic investigation of functionalized silicon films reveal features that are very different from that of bulk silicon and clearly bears signature of nanostructures. These thin films hold immense potential for applications in opto-electronic devices.
Poster Session II : Seguini G., Ben-Assayag G., Lindner J. K. N., Pellegrino P.
Authors : Ewa Dumiszewska, Jarosław Gaca, Marek Wójcik, Iwona Jóźwik, Włodzimierz Strupiński
Affiliations : Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw, Poland
Resume : Throughout the years, nanowires have become an essential material for optoelectronics. Free-standing semiconductor nanowires have recently attracted considerable attention due to their potential application in photovoltaic devices. The efficiencies of solar cells on nanowires have increased, reaching up to 13.8% for InP and 15.3% for GaAs materials. However, in order to further develop III-V nanowire solar cells, one still has to improve the quality of nanowires. Here in this work we have studied the influence of substrate preheating on growth of InP nanowires on (111)B substrates. The growth was carried out without using gold nanoparticles as a catalyst. All runs were carried out in an AIX 200 metalorganic vapour phase epitaxy (MOVPE) reactor. The source gases were TMIn and PH3. We achieved InP nanowires, the diameter of which varied. The quality of nanowires was inspected by means of XRD, XPS, SEM and Raman Spectroscopy.
Authors : Y. Melikhov, P. Konstantynov, Y. Syryanyy, J. Domagala, J. Sadowski, S. Kret, M. Chernyshova, and I.N. Demchenko
Affiliations : Institute of Physics PAS, Warsaw, Poland: Y. Melikhov; P. Konstantynov; Y. Syryanyy; J. Domagala; J. Sadowski; S. Kret; I.N. Demchenko Institute of Plasma Physics and Laser Microfusion, Warsaw, Poland: M. Chernyshova MAX IV Laboratoriet, Lund, Sweden: J. Sadowski
Resume : The effectiveness of classical molecular dynamics (MD) simulations for the interpretation of x-ray absorption fine structure (XAFS) of thermally activated decomposition of diluted magnetic semiconductors (DMS), namely, (Ga,Mn)As after medium temperature post growth annealing was tested. To determine the local atomic structure around Mn atoms XAFS spectra at Mn K-edge were gathered at ~70 K at BL22 beamline, ALBA. The annealed samples show reorganization of the near edge electronic structure and dramatic decrease of FT(R) amplitude with annealing temperature increase. Such behavior is a likely indicator of redistribution/diffusion of Mn atoms in the host matrix (high disorder), allowing to propose the following working hypothesis: starting from the randomly distributed substitutional Mn (referred as monomers), and point defects like interstitial Mn and As/Ga vacancies, formation of non-regular distributed areas of ?N-mers? (dimer, trimer and so on combined through As) could occur, which eventually could lead to formation of Mn-rich (Ga,Mn)As clusters. Based on our hypothesis we constructed the model supercells which are expected to correspond to different stages of annealing process. Averaging set of instantaneous atomic configurations obtained from NVT classical MD simulations was used to construct modelled XAFS spectra. Analysis of modelled and experimental XAFS spectra showed that the signal is combination of signals coming from monomers, ?N-mers?, and vacancies.
Authors : Priyadarsini. Swain, Suneel K. Srivastava, Sanjeev K. Srivastava
Affiliations : Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur-721302, INDIA; Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur-721302, INDIA; Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur-721302, INDIA
Resume : Metallic Ni1?xVx alloys are known to exhibit a ferromagnetic to paramagnetic disordered quantum phase transition (QPT) at the critical concentration xc 0.114 in bulk. Such a QPT is accompanied by a quantum Griffiths phase (QGP), the physical observables in which follow nonuniversal power-law temperature dependences, in a finite temperature range on the paramagnetic side of the transition. In the present work, we explore the occurrence of QGP in nanoparticles of this alloy system. Nanoalloys with x in the neighbourhood of xc and mean diameter 18-33 nm were prepared by a chemical reflux method. Following a few microscopic and spectroscopic studies to determine the sizes, compositions and phases, dc magnetization measurements were also performed to seek out any signature of QGP in the nanoalloys. A paramagnetic-like increase of magnetization is observed to emerge below an x-dependent transition temperature TP(x ) within the blocked ferromagnetic state of the nanoparticles, and is corroborated by a peak at TP(x ) in the temperature dependence of resistivity. The magnetic susceptibility in this emergent phase follows a non-Curie power-law temperature dependence below 10 K for 0:09 < x < 0:14, indicating the presence of a QGP in the nanoparticles within these temperature and composition ranges.
Authors : A.Vaitkevičius 1, J.Mickevičius 1, D.Dobrovolskas 1, H.Svidras 1, G.Tamulaitis 1, B.Foltynski 2, C.Giesen 2, M.Heuken 2
Affiliations : 1 - Institute of Applied Research and Semiconductor Physics Department, Vilnius University, Sauletekio 3, LT-10257 Vilnius, Lithuania; 2 - AIXTRON SE, Kaiserstr. 98, 52134 Herzogenrath, Germany
Resume : III-nitride nanowires have large surface-to-volume ratio, nearly dislocation-free lattice, diminished strain, however their growth on inexpensive and strongly lattice-mismatched silicon substrates still needs further study. We report on the spatially-resolved photoluminescence (PL) study in self-organized GaN rods with InGaN/GaN core-shell multiple quantum well (MQW) structures. The samples with three QWs deposited on the GaN rod sidewall facets and emitting in the range from 450 to 530 nm were grown by metalorganic chemical vapor deposition (MOCVD) on Si(111) substrate. PL spectroscopy in confocal mode was exploited in a wide range of excitation intensities. Inhomogeneous MQW PL intensity distribution was observed on the sidewalls of the rods. The density of the bright spots, corresponding to large PL intensity, changes with the vertical position on the rod. The emission pattern is quantum-dot-like at the bottom and more uniform at the top of the rods. The PL band does not shift as the excitation intensity is increased, since there is no strain-induced electric field in the nonpolar crystallographic orientation of the MQWs. The PL from the MQW is polarized perpendicular to the c-axis, as it is expected for nonpolar InGaN structures. The emission polarization ratio has the highest value of 0.54 at the top of the rod but decreases down to 0.14 at the bottom. The results show that InGaN/GaN core-shell structures of good quality can be grown on low-cost silicon substrates.
Authors : Mustafa Erkovan, Baha Sakar, Melek Türksoy Öcal, Osman Öztürk
Affiliations : Sakarya University, Nanoscience and Nanoengineering Dept. 54187, Sakarya, Turkey; Gebze Technical University, Physics Dept., Kocaeli, 41400, TURKEY
Resume : PtCo alloys are well known with their high catalytic properties, good corrosion resistance and magnetic properties. The equiatomic Pt50Co50 phase with L10 crystal structure is the best candidate for magnetic storage applications with its high magneto crystalline anisotropy. Achieving such anisotropy lies on well controlled stoichiometry and the structure of the crystal. In order to understand and control its properties, PtCo samples must be prepared with well controlled manner. This study focused on the growt mechanism of PtCo and variation of Pt/Co ratio Two different type of substrate used in the study are Pt(111) single crystal and a SiOx (111) wafer. Pure Co and Pt50Co50 samples are prepared on these two different substrates by Magnetron Sputtering at various temperatures (RT, 300⁰C, 450⁰C, 500⁰C and 550⁰C). Elemental composition and stoichiometry of the samples are analyzed by XPS and AES. UPS is used to understand the electronic structure of surfaces and the electronic interaction of the Pt and Co under different preparation conditions.To investigate the epitaxial growth and determine the surface symmetry, low energy electron diffraction (LEED) has been used. Results of samples prepared on Pt(111) indicate for the Co diffusion through the platinum substrate by the increasing temperature. Furthermore, either the Co or PtCo films grown on P(111) above 450°C have the same stoichiometry, surface symmetry and similar electronic properties. Results of the samples prepared on SiOx indicate for a bonding formation between Pt and Si with the increasing temperature while there is a significant electronic structure change in Co.
Authors : Mariusz Drygaś (1*), Jerzy F. Janik (1), Mirosław M. Bućko (2)
Affiliations : AGH University of Science and Technology, (1) Faculty of Energy and Fuels, (2) Faculty of Materials Science and Ceramics; Al. Mickiewicza 30, 30-059 Krakow, Poland *E-mail: firstname.lastname@example.org
Resume : In this report, described is a synthesis method for the preparation of GaN nanopowders from available GaE precursors (E = P, As, Sb) and discussed are competing reaction mechanisms operating during nitridation in the systems. High purity monocrystalline plates/chips of GaE (E = P, As, Sb) were either ground manually or using high energy ball milling. The resulting microcrystalline GaE powders were subjected to ammonolysis/nitridation under an ammonia flow at temperatures in the range 800-1100 C and for 6-150 h. Each of the precursors required specific conditions assuring complete nitridation. The substrates and the products were investigated by XRD supplemented with SEM/EDX, solid-state 71Ga MAS NMR, and Raman analysis. In all cases, the results confirmed the formation of pure nanocrystalline powders of GaN. Two GaN phases, i.e., hexagonal (h-GaN) and cubic (c-GaN), were often detected. For GaP, nitridation is thermodynamically controlled and yields pure h-GaN whereas for GaAs and GaSb some c-GaN is also formed supporting some contribution of topochemistry. In all precursor systems, the nitridation temperature and substrate particle size characteristics are key factors in controlling average crystallite size of GaN and the h-GaN/c-GaN ratio. Acknowledgement. The study was supported by the Polish National Science Center (NCN), Grant No. 2013/09/B/ST5/01223.
Authors : Jaemin Jung¹, Junghyo Nah², Min Hyung Lee*¹
Affiliations : ¹ Department of Applied Chemistry, Kyung Hee University, Yongin, Gyeonggi 17104, Korea; ² Department of Electrical Engineering, Chungnam National University, Daejeon 34134, Korea.
Resume : Development of advanced materials and structures for supercapacitor and battery is critical to achieve energy storage devices with high performance. Metal oxide/graphene hybrids can increase chemical and electrical coupling effects, and high surface area and electrical conductance of graphene are also attractive points as an advanced material for electrochemical devices. In this work, we present the selective growth of ZnO nanorod/reduced graphene oxide composites on graphene oxide film via IR laser-induced reaction. Optimized design of supercapacitor electrodes could be achieved by programming of laser scanning lines. The patterned complexes could be used as supercapacitor electrodes due to its pseudo capacitance (ZnO) and electric double layer capacitance (graphene).
Authors : M. Yu. Verbytska1, A. I. Falovska1, D. Matyash1, I.E. Kotenko1, Iu.N. Makogon1, Ya. A. Berezniak2
Affiliations : 1Kyiv Polytechnic Institute, National Technical University of Ukraine, 03056, Prospect Peremogy 37, Kyiv, Ukraine, email@example.com 2I.M. Frantsevich Institute for Problems of Material Science N.A.S of the Ukraine,03142, 3 Krzhizhanivs’ky Str., Kyiv, Ukraine
Resume : The use of additional layers of alloying elements with a low surface energy such as Ag, Au, or Cu in films based on the Fe50Pt50 alloy can accelerate ordering processes in films by changing the stress state in FePt layer and leads to reduction of L10 phase formation temperature. Internal stresses in the film depend not only on the film thickness and the type of substrate, but on the heating and cooling rate during annealing as well. The purpose of this study was to investigate the effect of annealing in hydrogen and adding of the intermediate Au layer on hard magnetic L10 phase formation in the Fe50Pt50(15 nm)/Au(7,5; 30 nm)/Fe50Pt50(15 nm) films deposited onto SiO2(100 nm)/Si(001) substrates. Films were deposited by means of magnetron sputtering. Heat treatment of the samples was carried out in a hydrogen ambient with a pressure 100 kPa in the temperature range of 500ºС - 800ºС for 30 s. The crystal structures and phase composition of the as-deposited and annealed films were characterized by x-ray diffraction on Ultima IV Rigaku diffractometer. Electric resistance was measured by four-probe method. It was revealed, that disordered A1-FePt phase is formed in as-deposited films. Phase transition of A1-FePt L10-FePt starts after annealing in hydrogen at 500°C. The ordering degree of L10-FePt phase increases as the annealing temperature rised up to 800°C. Oriented grain growth of L10-FePt phase in the  direction does not occur due to the dissolution of hydrogen in the lattice of L10-FePt. This is evidenced by an increase in the lattice parameter of c and c/a ratio of L10 phase. It was also observed the formation of Au hydrides, which is accompanied by electric resistance growth. It is found that axial textures  Au and  FePt in films take place and are more evident in films with a thicker Au interlayer of 30 nm. The authors would like to thank Prof. Dr. M. Albrecht from Augsburg University (Germany) and workers for sample preparation, assistance in conduction of investigations and discussion of results. This work was supported by DAAD Leonard Euler Scholarship Program 2015 – 2016 (DAAD Grant № 57198300)
Authors : O.V. Fihurna1, T.I. Verbytska1, O.V. Kucheriavyi2, А.Yu. Сhernysh1, I.E. Kotenko1, Iu.N. Makogon1
Affiliations : 1Kyiv Polytechnic Institute, National Technical University of Ukraine, 03056, Prospect Peremogy 37, Kyiv, Ukraine, firstname.lastname@example.org 2I.M. Frantsevich Institute for Problems of Material Science N.A.S of the Ukraine,03142, 3 Krzhizhanivs’ky Str., Kyiv, Ukraine
Resume : The use of FePt equiatomic composition films with ordered L10 phase as magnetic recording mediume can increase the density of the magnetic recording and storage information. This phase has a high magnetocrystalline anisotropy energy that prevents the superparamagnetic state transition with grain volume decrease. It is assumed that one of the ways to accelerate the process of ordering and decreasing the ordering temperature is to use the low surface energy of interfaces in the film composition and creation of stressed state by introducing an additional layer of the third element as Au, Ag or Cu. The aim of this work was to study the effect of Cu on magnetic hard L10-FePt phase formation in the layered [Fe50Pt50(15 нм)/Cu(7,5 нм)/ Fe50Pt50(15 нм)]n films, where n = 1, 2, at annealing in hydrogen. The films were deposited by magnetron sputtering on SiO2(100 nm)/Si(001) substrate kept at the ambient temperature. Annealing of samples in temperature range 5000С- 8000С for 30 s was carried out in a hydrogen atmosphere under pressure of 100 kPa. Phase composition and structure of the films was determined by X-ray phase analysis that was done on "Ultima IV Rigaku" diffractometer . It was established that the phase transition from the disordered A1 -FePt phase into the ordered L10-FePt phase begins after annealing at 500°C. In this case Cu is dissolved in the L10-FePt crystalline lattice that leads to reduction of c parameter. At increasing of annealing temperature an ordered ternary compound L10(FeCuPt) is formed and degree of ordering increases. The higher degree of ordering of L10(FeCuPt) phase is observes in multilayer [Fe50Pt50(15 nm)/Cu(7,5 nm)/Fe50Pt50(15 nm)]2 films. At the same time oriented grain growth of L10 (FeCuPt) phase in the direction of  is more evident in Fe50Pt50(15 nm)/Cu(7,5 nm)/Fe50Pt50(15 nm) films . The authors would like to thank Prof. Dr. M. Albrecht from Augsburg University (Germany) and workers for sample preparation, assistance in conduction of investigations and discussion of results. This work was supported by DAAD Leonard Euler Scholarship Program 2015 – 2016 (DAAD Grant № 57198300)
Authors : Urszula Klekotka, Beata Kalska-Szostko, Ewelina Wińska
Affiliations : Institute of Chemistry, University of Bialystok, Ciolkowskiego 1K, 15-245 Bialystok, Poland
Resume : Magnetic quasi-0D well-defined nanoparticles are widely investigated in many research fields, and the most popular ones being medicine and environmental protection. The least toxic commonly studied compound is magnetite. The reason of popularity of magnetite in nano form is its low toxicity and good biodegradability. In general, nanoparticles exhibit superparamagnetic behavior, but their blocking temperature can differ not only due to size or composition, but also to synthesis procedure, and surface modification. In the presented paper, we have prepared hybrid ferrite nanoparticles doped with Ca2+, Co2+, Mn2+, or Ni2+ respectively. For functionalization of nanoparticles, succinic or phtalic anhydrides, and 3-phosphonopropionic or 16-hexadecanoic acids were used. In the next step, controlled tests of binding of such pollution elements as Pb, Cu, Cd were done. The most effective compounds are the best for purification of solutions including drinking water from selected elements (in this case, heavy metals). Characterization of studied nanoparticles was done by Transmission Electron Microscopy, X-ray diffraction, and Mössbauer spectroscopy. Composites before and after attachment of elements were analyzed by IR and Raman spectroscopy. Solutions containing selected tested elements were measured by AAS.
Authors : Tommaso Jacopo Giammaria , Federico Ferrarese Lupi , Gabriele Seguini , Michele Perego , Diego Antonioli , Valentina Gianotti , Katia Sparnacci , Christopher Kemper Ober , Michele Laus .
Affiliations :  Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20846 Agrate Brianza (MB), Italy;  Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Viale T. Michel 11, Università del Piemonte Orientale “A. Avogadro", INSTM, Alessandria 15121, Italy;  Department of Materials Science and Engineering, Cornell University, Bard Hall, Ithaca, New York 14853, USA;  Nanoscience and Materials Division, Istituto Nazionale Ricerca Metrologica, Strada delle Cacce 91, Torino, Italy.
Resume : Diblock copolymers (DBCs) thin films have become the subject of an intense research activity because they self-assembly (SA) into periodic ordered nanostructures with different morphology. The DBCs containing polydimethylsiloxane (PDMS) have recently attracted a lot of attention because they form high-resolution nanostructures with dimensions below 10 nm, that can be exploited as nanolithographic masks perfectly suitable for microelectronic applications. The SA of the PDMS-containing DBCs can be achieved by means of different approaches but thermal annealing processes would be highly desirable. Interesting, the solvent employed to spin the DBC thin films plays an important role in the definition of the final morphology of the self-assembled nanostructures because the solvent could preferentially swell one of the blocks thus driving a specific morphology. In this work, we report a systematic study on the SA kinetic of cylinder-forming polystyrene-block-poly(dimethylsiloxane-random-vinylmethylsiloxane) PS-b-P(DMS-r-VMS) thin film, with molar mass of 22 Kg/mol (d = 9 nm, Lo = 20 nm), by means of a Rapid Thermal Processing (RTP) machine on flat surfaces using solvents casting with fixed selectivity but different boiling points and densities. The SA kinetic was evaluated considering the evolution of the lateral order (ξ) as a function of the annealing time (t) that follow a power law dependence of ξ ~ t^Φ, where Φ provides information about the kinetic grain coarsening.
Authors : Aliaksei Vetushka (1), Martin Müller (1), Martin Ledinský (1), Petr Pikna (1), Antonín Fejfar (1), Tomáš Baše (2)
Affiliations : (1) Institute of Physics, The Czech Academy of Sciences, Cukrovarnická 10, 162 00 Prague 6, Czech Republic; (2) Institute of Inorganic Chemistry, The Czech Academy of Sciences, 250 68 Husinec-Řež, č.p. 1001, Czech Republic
Resume : Electrical metal-semiconductor (Schottky) or semiconductor-semiconductor (p-n) junctions belong to basic elements of integrated circuits and various optical and-electronic devices. The key parameter of such elements is the presence of a potential barrier which determines its electrical behavior. The adjustment of the barrier’s electrical properties is thus very important. The general limitations of the primary methods (i.e. finding a metal/compound that produces the desired Schottky barrier height, or semiconductors doping) have been addressed in a number of studies and the respective solutions include insertions of organic molecular dipoles, insulating materials, and/or monolayer(s) of inorganic atoms, impurities, or defects at the interface. . The use of self-assembled monolayers (SAMs) is a highly innovative approach to adjust surface properties of metals, metal oxides, and semiconductors. The Schottky barrier height depends on the work-function of the particular metal substrate surface. It was already shown that silver work-function can be finely tuned over a range of 1 eV by SAMs of oriented carborane dipoles (1,2-(HS)2-1,2-C2B10H10 and 9,12-(HS)2-1,2-C2B10H10) which are chemisorbed onto silver surfaces through their sulfhydryl (-SH) groups [2–4]. The placing of SAMs of oriented dipoles in a semiconductor-semiconductor interface has not been addressed despite its obvious importance and potential for the barrier adjustment. In this contribution, we present the first results of carborane dipoles adsorption on silicon (111) surfaces. PeakForce AFM and Kelvin Probe Force Microscopy have been used for the local mapping/distribution of the adsorbed molecules.  R.T. Tung, The physics and chemistry of the Schottky barrier height, Appl. Phys. Rev. 1 (2014) 11304. doi:10.1063/1.4858400.  J.F. Lübben, T. Baše, P. Rupper, T. Künniger, J. Macháček, S. Guimond, Tuning the surface potential of Ag surfaces by chemisorption of oppositely-oriented thiolated carborane dipoles, J. Colloid Interface Sci. 354 (2011) 168–174. doi:10.1016/j.jcis.2010.10.052.  J. Kim, Y.S. Rim, Y. Liu, A.C. Serino, J.C. Thomas, H. Chen, Y. Yang, P.S. Weiss, Interface Control in Organic Electronics Using Mixed Monolayers of Carboranethiol Isomers, Nano Lett. 14 (2014) 2946–2951. doi:10.1021/nl501081q.  A. Vetushka, L. Bernard, O. Guseva, Z. Bastl, J. Plocek, I. Tomandl, A. Fejfar, T. Baše, P. Schmutz, Adsorption of oriented carborane dipoles on a silver surface, Phys. Status Solidi B. 253 (2016) 591–600. doi:10.1002/pssb.201552446.
Authors : FABIO ZANENGA (1,2), GABRIELE SEGUINI (1), KATIA SPARNACCI (2), MICHELE LAUS (2), MICHELE PEREGO (1)
Affiliations : (1) Laboratorio MDM, IMM-CNR, via C. Olivetti 2, 20864 Agrate Brianza (Italy) (2) Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Università del Piemonte Orientale, Viale T. Michel 11, 15121 Alessandria, Italy
Resume : Asymmetric polystyrene-b-polymethylmethacrylate (PS-b-PMMA) block copolymers (BCPs) can form perpendicularly oriented nanodomains since the surface interactions are easily balanced by grafting the appropriate P(S-r-MMA) random copolymer (RCP) to the surface. The development of long-range lateral order is a key requirement for BCP integration in nanolithographic processes. The self-assembly of asymmetric PS-b-PMMA BCPs with molecular weight (Mn) ranging from 54 to 132 kg/mol over a 2 or 19 nm thick grafted layer was accomplished through a fine tuning of the annealing temperature (TANN) and time (tANN) in a rapid thermal processing (RTP) machine. The grafted RCP brush layer acts as a reservoir of solvent: the thicker the brush layer, the higher the amount of solvent available for the self-assembly of the BCPs. Scanning electron microscopy inspection of the samples at different stages of the grain coarsening process allows investigating the grain-growth as a function of the RCP brush layer thickness and determining the growth rates for each BCP as a function of Mn. For the 19 nm thick RCP brush layer, the collected data indicate that the cooperative effect of solvent and temperature is sufficient to sustain the grain coarsening process over the range of tANN we explored; for each specific Mn, the growth exponent is constant at all the explored tANN. However the growth rates change as a function of Mn ranging from 0.07 for Mn=132 kg/mol to 0.34 for Mn=54 kg/mol.
Authors : F. Sgarbossa (1, 2), S. Carturan (1, 2), V. Boldrini (1, 2), G. Maggioni (1, 2), E. Napolitani (1, 2), D. R. Napoli (2), G.A. Rizzi (3), G. Granozzi (3), D. De Salvador (1, 2)
Affiliations : (1) Padua University, Physics and Astronomy Department, Via Marzolo n.8 Padova Italy; (2) Istituto Nazionale Fisica Nucleare, Laboratori Nazionali di Legnaro, Viale Università 1, Legnaro Italy; (3) Padua University, Department of Chemical Science, Via Marzolo n.1 Padova Italy;
Resume : Germanium is having a renewed interest as a strategic material for applications in photovoltaics, mid infrared and gamma detectors and especially in nano-electronics as a possible high mobility channel material in nano-transistors. The doping of such material in a locally controlled and conformal way at nanoscale will be an enabling technology for the real application in nano-electronic devices. To this aim the molecular doping approach can be a very interesting option not yet investigated on germanium. In this paper we grip different phosphorous containing molecules to the Ge surface. We demonstrate that the chemical reaction is active on Ge surface as well on Si and SiO2. Quantification by means of XPS and nuclear reaction analysies shows that a layer containing 1.2 x 10^15 P atoms/cm2 forms at the germanium surface after a wet gripping procedure followed by the cleaning of the physically absorbed component by means of methanol. The P containing layer is separated by the bare Ge by a Ge oxide thin layer. For comparison the same procedure forms a layer with 7x10^14 P atoms/cm2 on both Si or SiO2 surfaces. The results concerning the dopant activation and diffusion after the evaporation of a SiO2 capping layer and thermal treatments will be presented.
Authors : VALENTINA GIANOTTI, DIEGO ANTONIOLI, KATIA SPARNACCI, MICHELE LAUS, TOMMASO JACOPO GIAMMARIA, MONICA CERESOLI, FEDERICO FERRARESE LUPI, GABRIELE SEGUINI, MICHELE PEREGO
Affiliations : VALENTINA GIANOTTI, DIEGO ANTONIOLI, KATIA SPARNACCI, MICHELE LAUS DISIT, University of Piemonte Orientale, Alessandria, 15121, Italy; TOMMASO JACOPO GIANMARIA, MONICA CRESOLI, FEDERICO FERRARESE LUPI, GABRIELE SEGUINI, MICHELE PEREGO, Laboratory MDM, IMM-CNR, Agrate Brianza, 20864, MB, Italy
Resume : Grafted multicomponent polymeric systems represent the starting point for the creation of scaled high-resolution polymer nanostructures including nanometer scale membranes, templates for fabrication of nanoobjects such as metal, ceramic nanodots and wires, and nanopattern masks for subsequent additive or subtractive processing of the underlying substrate. In addition, the exploitation of more sophisticated surface interactions, such as various directed self-assembly (DSA) approaches, can lead to structures featuring improved lateral ordering and reduced structural defects. From the analytical point of view, these systems can be conceived as ultrathin films (h < 10 nm) of polymer chains grafted to a solid substrate. Consequently, their evaluation represents a rather demanding analytical task due to the very small amount of material to be detected. Moreover, these materials should be analyzed still grafted to the substrate because their detachment from the surface implies major structural modifications. These two distinct requirements limit the number of analytical techniques suitable to obtain information about their structure and composition. The use of hyphenated thermal and mass spectrometric techniques is well established and widely applied to the investigation of the polymer structures under distinct thermal conditions. Recently in our laboratory a highly versatile TGA-GC-MS apparatus was developed1 and successfully applied2,3 to the analysis of a number of samples featuring substantial scale difference, i.e. bulk materials, thick films (few µm), thin (dozens of nm), and ultrathin films (few nm) without any sample pretreatments. In the present contribution, the TGA-GC-MS technique was addressed to the quantitative determination of the composition of ultrathin films obtained from the “grafting to” of functional PS-b-PMMA and P(S-r-MMA) copolymers. The calibration of the system was performed by model systems of functional P(S-r-MMA) with different composition. Once the system calibration was properly set up, the grafting process of binary mixtures of functional polymethylmethacrylate (PMMA) and polystyrene (PS) homopolymers to an activated and preferential silicon surface was elucidated. 1 Gianotti, V., Antonioli, D., Sparnacci, K., Laus, M., Giammaria, T. J., Ceresoli, M., Ferrarese Lupi, F., Seguini, G. & Perego M., J. of Chromatography A, 1368, 204-210 (2014). 2 Ceresoli,M., Palermo, M., Ferrarese Lupi, F., Seguini, G., Perego, M., Zuccheri, G., Phadatare, S.D., Antonioli, D., Gianotti, V., Sparnacci, K. & Laus, M., Nanotechnology, 26, 415603 (2015). 3 Antonioli, D., Sparnacci, K., Laus, M., Ferrarese Lupi, F., Giammaria, T. J., Seguini, G., Ceresoli, M., Perego, M. & Gianotti, V., Analytical and Bioanalytical Chemistry, doi: 10.1007/s00216-016-9380-8.
Authors : DIEGO ANTONIOLI, KATIA SPARNACCI, VALENTINA GIANOTTI, MICHELE LAUS, TOMMASO JACOPO GIAMMARIA, MONICA CERESOLI, FEDERICO FERRARESE LUPI, GABRIELE SEGUINI, MICHELE PEREGO
Affiliations : DIEGO ANTONIOLI, KATIA SPARNACCI, VALENTINA GIANOTTI, MICHELE LAUS DISIT, University of Piemonte Orientale, via Michel 11, Alessandria, 15121, Italy TOMMASO JACOPO GIAMMARIA, MONICA CERESOLI, FEDERICO FERRARESE LUPI, GABRIELE SEGUINI, MICHELE PEREGO Laboratory MDM, IMM-CNR, Agrate Brianza, 20864, MB, Italy
Resume : Tailoring surface energies is the key factor to control the orientation of nanoscopic structures in block copolymer (BCP) thin films. Perpendicular orientation of the BCP features can be achieved with non preferential interactions at both the bottom and top interfaces. A common approach to the formation of a neutral surface consists in using end-functional poly(A-r-B) random copolymers to induce the perpendicular orientation of polyA-b-polyB diblock copolymers. As the random copolymer chemical composition can be precisely controlled, a fine-tuning of the surface characteristics is possible. In this work, a series of hydroxyl terminated poly(styrene-r-methyl methacrylate) random copolymers was prepared, with equal composition but different molar masses, ranging from 1700 to 69000 g/mol. The Rapid Thermal Processing (RTP) technology was employed to perform flash grafting reactions of the random copolymers to the activated silicon wafer surface at different temperatures for time periods ranging from few seconds to several minutes. The characteristics of the grafted layer were delineated as a function of the molar mass of the random copolymers. The subsequent ordering propensity of a symmetric polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymer was found to be dependent on both the grafting temperature and the molecular weight of the random copolymer employed. Efficient neutral wetting brush layers with thickness lower than 2 nm were obtained. These results shed new light on the nature of the surface neutralization and indicate that several concepts and preconceptions of the molecular design of the self assembling materials should be reconsidered.
Authors : D.Antonioli, V. Gianotti, K Sparnacci, D. Comoretto, M. Laus
Affiliations : D.Antonioli, V. Gianotti, K Sparnacci, M. Laus Dipartimento di Scienza dell?Ambiente e delle Vita, Viale T. Michel 11, Università del Piemonte Orientale ?A.Avogadro?, INSTM, UdR Alessandria, 15121 Alessandria, Italy D.Comoretto Diparimento di Chimica e Chimica Industriale, Università degli Studi di Genova, Via Dodecaneso 31, 16146 Genova, Italy
Resume : Monodisperse colloidal spheres have emerged as the material of choice for a wide variety of applications that range from nanopattering to fabrication to photonic devices. These materials represent the simplest class of building blocks that can be readily assembled into two or three dimensionally ordered structures. A variety of colloids can be synthesized as truly monodispersed systems in which the size and shape of the particles and the net charges that are chemically fixed on their surfaces are all identical to within 1-2%. As the preparation of nanostructured materials involves essentially the use of monodispersed particles in the 10 nm to 1 micrometer size range, heterophase polymerizations are the techniques of election. They comprise a variety of different processes including suspension, dispersion, emulsion as well as nanoemulsion polymerizations. A related approach to prepare such nanosized particles relies on the seeded emulsion technique starting from seeds of a few nanometers. These can be prepared in situ by a self-seeding technique or can derive from a distinct preparation. In this presentation, we describe the preparation of PTFE/PMMA core-shell nanoparticles, featuring controlled size and narrow size distribution, through a seeded emulsion polymerization starting from a PTFE seed of 41 nanometers. A very precise control over the particle size can be exerted by properly adjusting the ratio between the monomer and the PTFE seed. The high degree of PTFE compartmentalization resulted in a very peculiar crystallization behavior of the resulting composite nanoparticulate systems. Particles in the 100-350 nm range can be prepared with uniformity indexes suited to build 2D and 3D colloidal crystals. A linear correlation is observed between sphere diameter and stop band wavelength. As the diameter decreases, the stop band shifts to lower wavelengths. Angle-resolved transmittance measurements are performed with linearly polarized light with its electric field perpendicular (s-polarization) or parallel (p-polarization) to the incidence plane. With increasing angle of incidence, not only the position and intensity but also the shape of the transmittance peak modified, in a way strictly dependent from light polarization direction.  M. Laus, K. Sparnacci, D. Antonioli, S. Deregibus, V. Kapeliouchko, G. Palamone, T. Poggio, G. Zuccheri, R. Passeri. On the multiple crystallization behavior of PTFE in PMMA/PTFE nanocomposites from core-shell nanoparticles. J. Polym. Sci. Part B-Polym. Phys. 2010 48 548-554.  E. Pavarini, L.C. Andreani, C. Soci, M. Galli, F. Marabelli, and D. Comoretto. Band structure and optical properties of opal photonic crystals. Phys. Rev. B72, 045102-1/045102-9 (2005).
Authors : Y. Gucbilmez a, I. Calis b, A.S. Yargic c
Affiliations : a Department of Chemical Engineering, Anadolu University, 26555, Eskisehir, Turkey; b Betareks Metalize İplik ve Ambalaj San. A. S., 54600, Sinop, Turkey; c Department of Chemical and Process Engineering, Bilecik Seyh Edibali University, 11230, Bilecik, Turkey
Resume : In the content of this study, previously synthesized 3% by weight palladium incorporated MCM-41, MCM-48 and SBA-15 type catalysts were characterized by the XRD, BET, Chemisorption and SEM methods. All three catalysts had good crystalline patterns and high BET surface areas in the region of 600-900 m2/g. Highest BET surface area and pore volume was found for the 3%-Pd-MCM-48 catalyst due its three-dimensional pore structure while the 3%-Pd-SBA-15 catalyst had the largest active (metal) area. Incorporation of the palladium metal did not deteriorate the particle structure for the MCM-41 and SBA-15 type catalysts however it caused some agglomeration for MCM-48. Dispersion of the palladium metal was also highest for the SBA-15 type catalyst which suggests this catalyst probably will be the most active one in oxidation reactions.
Authors : GIULIA APRILE (1,3), LUCA BOARINO (1), SARA TADDEI (2), ELISA MARTINELLI (2), GIANCARLO GALLI (2), KATIA SPARNACCI (3) AND MICHELE LAUS (3)
Affiliations : (1) Nanoscience and Materials Division, Istituto Nazionale Ricerca Metrologica, Strada delle Cacce 91, 10135 Torino (Italy) (2) Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa (Italy) (3) Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Università del Piemonte Orientale ‘‘A. Avogadro’’, Viale T. Michel 11, 15121 Alessandria (Italy)
Resume : Diblock copolymers (DBCs) are extensively investigated as key materials for lithografic applications. The integration of conventional top-down approaches with the bottom-up self-assembly allows DBC films to be employed as precisely registered organic templates. In order to satisfy the requirements of the industrial nanofabrication technology, lots of efforts are devoted to scale down the dimension of the DBC lattice parameters. However, DBC materials have a limitation of their self-assembly properties depending on the product between the Flory-Huggins parameter χ and molecular weight Ν. Conventional lithographic materials, like polystyrene-block-polymethylmethacrylate (PS-b-PMMA), show a low χ which limits their application at sub-10 nm scale, and therefore new high-χ materials have to be synthesized. In this work a series of PS-b-P(MMA-r-AF6) block copolymers (10 kg/mol) were prepared via ATRP with a gradient increment of 2-(perfluorohexyl)ethyl acrylate (AF6) units. The self-assembly events of these DBCs were studied by using a Rapid Thermal Processing (RTP) oven both on flat silicon surface and inside SiO2 periodical trenches. The fluorinated DBC thin films were characterized by contact angle, XPS and SEM analyses. A comparison between these high-χ materials and the conventional ones is useful to understand how tailoring the synthesis of fluorinated DBCs can help to overcome the imposed energetic limitation.
Authors : R. Milazzo,(1) G. Impellizzeri,(2) A. La Magna,(3) D. Scarpa,(4) S. Boninelli,(2) A. Sanson,(1) D. De Salvador,(1) M. Linser,(1) A. Andrighetto,(4) A. Portavoce,(5) D. Mangelinck,(5) J. Slotte,(6) F. Priolo,(2,7) V. Privitera,(2) G. Fortunato,(8) A. Carnera,(1) and E. Napolitani(1)
Affiliations : (1) CNR-IMM Matis and Dipartimento di Fisica e Astronomia, Università di Padova, via Marzolo 8, 35131 Padova, Italy (2) CNR-IMM Via S Sofia 64, I-95123 Catania, Italy (3) CNR-IMM , Z.I. VIII Strada 5, 95121 Catania, Italy (4) INFN Laboratori Nazionali di Leganro, Italy (5) IM2NP, CNRS-Universités d?Aix-Marseille et de Toulon, Marseille, France (6) Department of Applied Physics, Aalto University, P.O. Box 11100, FI-00076 AALTO, Finland (7) Dipartimento di Fisica e Astronomia, Università di Catania, Via S Sofia 64, I-95123 Catania, Italy (8) CNR-IMM, Via del Fosso del Cavaliere 100, 00133 Roma, Italy
Resume : Achieving highly-doped shallow layers in germanium is a major challenge for advanced device development in many fields such as nano- and opto-electronics, photonics, sensors, etc. To this purpose pulsed laser melting, subsequent to ion implantation, is studied as being able to promote ultra-fast liquid phase epitaxial regrowth in a shallow layer. As a consequence, dopants are activated well above the equilibrium solid solubility while confining the diffusion within the molten layer. Latest results on electrical activation, diffusion, residual defects, contaminations, thermal stability will be presented for both p- and n-type doping of Ge in a wide range of experimental conditions.
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Optical and Plasmonic Applications II : Norris D. J.
Authors : K. Dohnalova (a), B. van Dam (a), H. Nie (b), M. Li (c), C. I. Osorio (d), F. Koenderink (d)
Affiliations : (a) University of Amsterdam, Amsterdam, The Netherlands; (b) University of Twente, Enschede, The Netherlands; (c) Jilin University, Changchun, China; (d) AMOLF Institute, Amsterdam, The Netherlands
Resume : Silicon- and Carbon- quantum dots (Si-QDs and C-QDs) have been recently proven to offer bright light emission with tunable color through the whole visible range [1-5]. Both materials are non-toxic and bio-degradable, can be (bio-) functionalized by virtually any organic molecule via strong covalent bond. Both can be prepared from resources that have virtually unlimited availability, such as sand, rice or bamboo for Si-QDs and various low cost organic materials for C-QDs. Si-QDs have also been shown in past to offer outstanding photo-chemical stability. This is in striking contrast to the currently employed nanostructures in optoelectronics or medical imaging, where health- or environment-risk materials (Cd, Pb, As, Zn, Se, …) or materials that are rare or expensive (In, Te, Rare Earths, Au, …) are in use. This situation occurs because Si-QDs have been known for inefficient and color-limited light emission  and C-QDs are still relatively new material with unresolved questions over origin of emission, stability and color-tunability . In our work [1-4,6], we research optical properties of both Si-QDs and C-QDs, with goal to find the most efficient and broadly tunable light emitting system. As the size-dependent optical properties of semiconductor QDs make it difficult to uncover the origin of the underlying processes from ensemble spectroscopy only, we use combination of ensemble spectroscopy and single-QD-spectroscopy. This allows us to study properties of individual emitters that are otherwise obscured in ensemble measurements, like size-dependent emission spectra, blinking and size-dependent radiative rate. In particular, we focus on (i) possible enhancements of the radiative rate by ligand-induced modifications of the band-structure and (ii) spectral enhancements using induction of various color sites in both materials.  K. Dohnalova, K. Kusova, T. Gregorkiewicz, J. Phys.: Condens. Matter 26 (2014) 173201  A.N. Poddubny, K. Dohnalova, Phys. Rev. B 90 (2014) 245439  K. Dohnalova et al., Light: Science & Applications 2 (2013) e47  K. Dohnalova et al., Small 8 (2012) 3185  H. Nie et al., Chem. Mater. 26 (2014) 3104  B. van Dam, H. Nie et al., “Multi-chromatic carbon dots”, in preparation (2016)
Authors : Jaime Martín, Marisol Martín-González.
Affiliations : Department of Materials and Centre for Plastic Electronics, Imperial College London, SW7 2AZ London, United Kingdom, Instituto de Microelectrónica de Madrid (IMM-CSIC), Calle de Isaac Newton 8, 28760 Tres Cantos, Madrid.
Resume : Three-dimensional nanoestructures combine properties of nanoscale materials with the advantages of being macro-sized pieces when the time comes to manipulate, measure their properties, or fabricate a device. However, the amount of compounds that have the ability to self-organize in ordered here-dimensional nanostructures is limited. Therefore, template-based fabrication strategies become the key approach towards three-dimensional nanostructures. Here we report the straightforward fabrication of a template based on anodic aluminum oxide, having a well-defined, ordered, tunable, homogeneous 3D nanotubular network in the sub 100 nm range . The used fabrication approach includes a pulsed anodization process of aluminium, in which we anodize at constant voltage during Mild Anodization steps and at a defined current during the Hard Anodization pulses; followed by a chemical etching process, in which the aluminum oxide grown under HA regime is partially dissolved. The 3D-AAO thus formed possessed a hexagonal array of longitudinal nanopores (40 nm in diameter), perpendicularly interconnected through transversal nanochannels (20-35 nm in diameter). The number and the distance between the transversal nanopores can be simply adjusted selecting the amount and the length of the MA steps. The three-dimensional templates are then employed to achieve three-dimensional, ordered nanowire-networks in polymers. Lastly, we demonstrate the photonic crystal behavior of both the template and the polymer three-dimensional nanostructure. Our approach might stablish the foundations for future high-throughput, cheap, photonic materials and devices made of commodity plastics, for example. 1. Martín J, Martín-González M, Francisco Fernández J, Caballero-Calero O. Ordered three-dimensional interconnected nanoarchitectures in anodic porous alumina. Nature Communications. 2014;5.
Authors : Florian Maudet, Fabien Paumier, Thierry Girardeau
Affiliations : Institut Pprime ,Université de Poitiers- CNRS-SP2MI-BP 30179, 86962-Chasseneuil-Futroscope cedex- France; Institut Pprime ,Université de Poitiers- CNRS-SP2MI-BP 30179, 86962-Chasseneuil-Futroscope cedex- Frances; Institut Pprime ,Université de Poitiers- CNRS-SP2MI-BP 30179, 86962-Chasseneuil-Futroscope cedex- France
Resume : Bottom-up processes like GLancing Angle Deposition (GLAD) of thin films and complex multilayers have attracted much attention in the recent years because of a large variety of technological applications in the field of photonic. The 3D nanostructures engineered exhibit optical, electrical and mechanical properties that differ from classical dense thin films. The GLAD process results, by a shadowing effect, to the conception of highly porous nanostructured materials. The morphology of theses 3D nanocolumns can be controlled by varying different deposition parameters like the substrate’s deposition angle, the deposition rate or the substrate temperature. A large panel of materials (oxides, semiconductors…) deposited by both sputtering and evaporation PVD in GLAD configuration, were studied for different depositions parameters. Our work is focused on the study of the relationship between the nanostructures (characterized by X-Ray Diffraction and SEM) and their optical properties through the modelling and the control of the refractive index gradient profile tuned by the porosity insertion. These optical properties were extracted from ellipsometric and spectrophotometric measurements made on a large spectral range going from the visible to the Midwavelength infrared. From this study we were able to obtain “new” optical properties leading to AR coatings with an ultra-high level of transmittance on a large wavelength range respectively in the visible and Midwavelength Infrared one.
Authors : Mathias Bourg, Martin Urbanski
Affiliations : Mathias Bourg, University of Luxembourg; Martin Urbanski, University of Luxembourg;
Resume : Composites of self-organizing liquid crystal host phases and functionalized nanoparticles offer great opportunities both for basic science and new applications. In our present study we investigate the dielectric properties of nematic liquid crystal / gold nanoparticle composites and introduce new aspects to the fundamental understanding of interactions between nanoparticle dopants and liquid crystalline host phases: We report that functionalized nanoparticles contaminate the LC host phase with mobile ions and considerably increase its conductivity. Consequently, the electro-optic performance of such nanocomposites suffers from ion drift and interfacial polarization, phenomena which have been rarely associated with liquid crystal nanocomposites so far. We demonstrate that a simple space charge model provides a plausible explanation for the observed impact of nanoparticles on the electro-optic performance and is superior to alternative models reported in literature. Beyond probing the electro-optical performance, we use dielectric spectroscopy also to study dipolar relaxation modes of the host molecules in the presence of various dopants (nanospheres, nanorods). By analysing the impact of nanoparticles on the molecular relaxation times of the nematogenic molecules and the activation energy for molecular reorientation we find that the presence of nanoparticles, surprisingly, does not verifiably alter the uniaxial orientational ordering of the nematic host phase.
Authors : Subhrangshu Choudhury, Mallar Ray,Subrata Chatterjee, Shyamal Kumar Saha
Affiliations : Dr. M. N. Dastur School of Materials Science and Engineering,Indian Institute of Engineering Science and Technology,Howrah,India;Dr. M. N. Dastur School of Materials Science and Engineering,Indian Institute of Engineering Science and Technology,Howrah,India;Dr. M. N. Dastur School of Materials Science and Engineering,Indian Institute of Engineering Science and Technology,Howrah,India;Department of Materials Science,Indian Association for the Cultivation of Science,Kolkata,India
Resume : Silicon, an indirect bandgap semiconductor is one of the most important and intensively studied materials despite being an inefficient light emitter. Si with nano scale dimensions can be coaxed to emit visible light with relatively high efficiencies. Understanding the luminescence process in Si nanocrystals (NCs) has remained challenging. We have synthesised Si nano structures via an inexpensive technique of mechanical milling followed by deliberate oxidation-etching-oxidation. We subsequently successfully encapsulated these luminescent Si NCs inside a solid block of polystyrene. Structural and optical investigations reveal that polystyrene encapsulates and protects the Si NCs. Distinct peaks corresponding to Braggs reflection of (111), (220), and (440) of Si crystals are seen in the X-ray diffraction profile. Bright field Transmission Electron Microscopy (TEM) images showed some dark spots and fringes which are signatures of Si NCs. From the optical characteristics it is seen that the Uv-visible absorption commences from 410 nm with a peak at 290 nm. Photoluminescence spectra of the nanocomposite shows highest intensity of emission at ~ 420nm.Thin film of polystyrene encapsulated Si NCs was spin coated on a Transparent conducting oxide (TCO) sandwiched between a Electron Transport Layer (ETL) of Alq3 and Hole Transport Layer (HTL) of PEDOT.PSS. Ohmic contacts were established to form a device which emits room temperature electroluminescence detectable with unaided eye.
Nanostructures: Characterizations and Applications I : Stéphan O.
Authors : Franz-Philipp Schmidt (1, 2), Harald Ditlbacher (1), Ulrich Hohenester (1), Andreas Hohenau (1), Joachim R. Krenn (1) , Ferdinand Hofer (2)
Affiliations : (1) Institute of Physics, University of Graz, Austria; (2) Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Austria
Resume : Plasmonic nanostructures enable the concentration of light to the deep subwavelength regime and, thus, are the topic of intense fundamental and application oriented research. Nanoparticles acting as optical antennas are well known for their nanoscale mode volumes, due to the excitation of localized plasmon modes. In this context electron energy-loss spectroscopy (EELS) in a transmission electron microscope (TEM) became a powerful technique as it enables to map the full modal spectrum of plasmon eigenmodes with unprecedented high spatial resolution . In this work we present an EELS study of plasmon eigenmodes on single metallic nanoparticles prepared by means of electron beam lithography. First we identify two different types of plasmon modes on silver nanodisks, i. e. film and edge modes . Second we show that coupling of edge plasmon modes within a single rectangular nanoparticle leads to mode splitting and the formation bonding and antibonding edge modes. These experimental observations together with a theoretical study in the form of boundary element method (BEM) simulations  lead us to universal scaling rules, connecting the nanodisk spectrum to the surface plasmons of extended films and edges. Furthermore the coupled edge mode model straightforwardly explains the mode energies in dependence of the nanoparticle geometry and is thus an effective tool for the understanding and tailoring of plasmonic mode spectra.  Nelayah et al., Nat. Phys. 3 (2007), 348−353.  F.P. Schmidt et al, Nat. Commun. 5 (2014), 3604.  U. Hohenester and A. Truegler, Comp. Phys. Commun. 183 (2012), 370.  This work was supported by the FWF SFB NextLite (F4905-N23 and F4906-N23), ESTEEM2 (FP7 project, no. 312483), NAWI Graz, and the Graz Centre for Electron Microscopy (ZFE).
Authors : Leslie Schlag, Jun Fang, Thomas Stauden, Jörg Pezoldt, Peter Schaaf, Heiko O. Jacobs
Affiliations : Leslie Schlag, Fachgebiet Nanotechnologie, Technische Universität Ilmenau, Gustav-Kirchhoff-Strasse 1, D-98693 Ilmenau, Germany; Jun Fang, Electrical and Computer Engineering, University of Minnesota, 200 Union St. SE, Minneapolis, MN 55455, United States; Thomas Stauden and Jörg Pezoldt, Fachgebiet Nanotechnologie, Technische Universität Ilmenau, Gustav-Kirchhoff-Strasse 1, D-98693 Ilmenau, Germany; Peter Schaaf, Fachgebiet Werkstoffe der Elektrotechnik, Technische Universität Ilmenau, Gustav-Kirchhoff-Strasse 5, D-98693 Ilmenau, Germany; Heiko O. Jacobs, Fachgebiet Nanotechnologie, Technische Universität Ilmenau, Gustav-Kirchhoff-Strasse 1, D-98693 Ilmenau, Germany
Resume : This talk will present a self-aligned nanowire bonding process to form free-standing point-to-point electrical connections. Wire diameters down to 200 nm and contact pads down to 1 µm will be shown. Moreover, the process is a parallel process to achieve a higher throughput when compared with any of the emerging serial-direct-write or established serial wire bonding methods. The presented process is based on a method that is best referred to as “gas phase electrodeposition”. The process has been described in parts before[2,3]. The relevant elements as it is known so far are briefly described to put the current research in context. First it is a localized material growth/deposition process which uses charged insulators to attract or deflect an incoming flux of charged material. Taking a closer look at the basic process, it becomes clear that gas phase electrodeposition shares some of the characteristics of electrodeposition in the liquid phase. However, it is a gas phase process with a much larger mean free path of the particles. The Debye length representing the screening length of Coulomb forces is also larger. Despite this difference, it can grow nanostructures in selected domains in a programmable fashion by adjusting the dissipation current of the ionic species that arrive at the surface. For example, in the simplest case it was used to grow straight metallic nanowire arrays whose height and density were adjusted to vary across the substrate which in turn were used as contacts in photovoltaic devices. Others have used this technique to fabricate metallic nanostructures for surface enhanced Raman spectroscopy (SERS)[7,8]. In any event, charged material continues to deposit into locations where charge dissipation can occur, leading to a growth of extended structures much like what is observed in the liquid phase based electrodeposition/plating. References  J. Fang, L. Schlag, S. C. Park, Th. Stauden, J. Pezoldt, P. Schaaf, H. O. Jacobs, Advanced Materials, 2016, 28 (9).  J. J. Cole, E. C. Lin, C. R. Barry, H. O. Jacobs, Small 2010, 6 (10).  E. C. Lin, J. J. Cole, H. O. Jacobs, Nano Letters 2010, 10 (11).  H. O. Jacobs, G. M. Whitesides, Science 2001, 291 (5509).  A. M. Welle, H. O. Jacobs, Applied Physics Letters 2005, 87 (26).  C. R. Barry, H. O. Jacobs, Nano Letters 2006, 6 (12).  E. C. Lin , J. Fang , S. C. Park , T. Stauden , J. Pezoldt, H. O. Jacobs, Advanced Materials 2013, 25 (26).  J. Fang, S. C. Park, L. Schlag, T. Stauden, J. Pezoldt, H. O. Jacobs, Advanced Functional Materials 2014, 24 (24).
Authors : S. Costanzo, G. Simon, Ph. Colomban, I. Lisiecki.
Affiliations : Sorbonne Universités, UPMC Univ Paris 06, UMR 8233, MONARIS, 4 Place Jussieu, 75005, Paris, France CNRS, UMR 8233, MONARIS, 4 Place Jussieu, 75005, Paris, France
Resume : Two (2D) and three (3D) ordered assemblies (supracrystals) have been prepared by dropwise deposition and immersing process respectively,(1) of a colloidal solution of Co nanoparticles, which size control have been obtained through a new chemical route, allowing TEM and Raman (low wavenumber) characterization. Chemical reduction of Co(AOT)2 precursors with NaBH4 and solvent selection (isooctane, hexane, cyclohexane, xylene, cumene, decane, octane) leds to uniform cobalt nanoparticles with tunable size ranging from 3.9 to 9.3 nm and their 2D and 3D ordering. TEM was performed using a JEOL JEM-1011 microscope operating at 100 kV, a JEOL 2010 microscope at 200 kV and a Nion Ultrastem 100 scanning transmission electron microscope operating at 100 kV. A HR800 LabRam setup from Horiba Scientific Jobin Yvon, working with 514.5-nm laser excitation and equipped with BragGrate notch filters were used. We report here the first observation of (polarized) low wavenumber Raman signature of ordered assemblies with particles ranging from ~4 to 9 nm in the 100-350K temperature range (2). The mode at the lowest wavenumber, pointed at 3 to 10 cm-1, is attributed to the quadrupolar (l= 2) mode while the second one, at 17 to 25 cm-1, is attributed to the breathing Lamb’s mode (l = 0). The wavenumber of these modes is reciprocal to the inverse particle diameter as was confirmed analyzing different particles with different size developed recently(3) . This observation shows that Plasmon-phonon coupling is not mandatory to observe Lamb’s metal particle modes if high sensitivity high resolution instruments are used. Furthermore, we point out the utility of Low Wavenumber Raman Spctroscopy to determine the average particles size. 1- I. Lisiecki, P.A. Albouy and M.P. Pileni Adv. Mat. 15 (2003) 712. 2- G. Simon, L. Meziane, A. Courty, I. Lisiecki, Ph. Colomban, J. Raman Spectrosc. 47 (2016) 248. 3- S. Costanzo, G.Simon, J. Richardi, Ph.Colomban end I.Lisiecki. Submitted to Chemistry of Materials.
Authors : Toshihiko Tanaka, Shinya Matsumoto, Tetsuya Aoyama,Takashi Kobayashi, Jean Charles Ribierre
Affiliations : National Institute of Technology, Fukushima College, Japan; Department of Environmental Sciences, Faculty of Education and Human Sciences, Yokohama National University, Japan; Elements Chemistry Laboratory, RIKEN, Japan; School of Engineering, Osaka Prefecture University, Japan; Center for Organic Photonics and Electronics Research, Kyushu University, Japan.
Resume : J-aggregates still have attracted attention although their applications to photography have gone out of use. Because of their low dimensionality, macroscopic orientation enhances their properties in a direction, thereby being favorable in applications such as nonlinear optics and semiconducting devices. We report here the J-aggregates oriented on aligned polytetrafluoroethylene (PTFE) layers. They are partially formed in the films from 5 dyes deposited on the layers. Large dichroic ratios (D) due to high orientation are often shown: two dyes show D from 20 to 44 in polarized absorption spectra. The film of a bisazomethine of the two also has been successfully applied to ambipolar organic field effect transistors. We sometimes have the substrate effect where J-aggregates are not formed on glass, demonstrating the induction of J-aggregates by the layers. The origin of the effect will be discussed in terms of the driving force of the orientation. The effect suggests its advantage: the oriented aggregates could be obtained from various molecules.  T.Tanaka, et al., J.Phys.Chem.C,115,19598(2011);  T.Tanaka, et al., Chem.Lett.,40,1170(2011);  T.Tanaka, et al., Chem.Lett.,42,34(2013);  T.Tanaka, et al., Chem.Lett.,44,462(2015);  T.Tanaka, et al., Langmuir, 32,4710(2016);  J.C.Ribierre, et al., RSC Adv.,4,36737(2014).
Authors : Francesco Bruni(1), Jacopo Pedrini(1), Maria Rosa Antognazza(2), Caterina Bossio(2), Francesco Meinardi(1), Guglielmo Lanzani(2,3) and Sergio Brovelli(1)*
Affiliations : (1)Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, via Cozzi 55, IT-20125 Milano, Italy (2)Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Via Pascoli 70/3, 20133 Milano, Italy. (3) Politecnico di Milano, Dip.to di Fisica, Piazza L. Da Vinci 32, 20133 Milano, Italy. *email@example.com
Resume : Intracellular pH sensing is a key diagnostic tool for many biological mechanisms, such as ATP hydrolysis, cancer formation and brain or heart diseases. Photoluminescence (PL) microscopy with conventional pH sensors is limited by the need of radiometrically measuring their PL intensity in biological samples. This is boosting the interest for multifunctional probes with ratiometric response arising from the different pH sensitivity of co-existing emissive states. Current ratiometric probes are complex systems consisting of inorganic nanostructures coupled to organic dyes, which suffer the poor stability of organic systems and cross-readout issues due to their broad PL spectra. Here, we overcome all these limitations by demonstrating the first ratiometric single-particle pH probe based on fully inorganic nanocrystals (NCs) featuring high stability and narrow PL spectra. We use bio-compatiblized dual emitting core/shell CdSe/CdS NCs exhibiting core and shell PL with different pH sensitivity due to the different exposure of the respective excitons to the environment: the core PL is unaffected by the pH, while the shell PL undergoes drastic enhancement in the 3-11 pH range, resulting in a cross-readout-free ratiometric response of 600%. In vitro microscopy of HEK cells demonstrates that the ratiometric response in biologic media fully resembles far field pre-calibration PL experiments, which we further use for real-time monitoring an externally induced pH variation in living cells.
Authors : Vanessa Belaud (a) (b), Ophélie Rimbaud (a) (b), Stéphane Benayoun (a), Karine Anselme (d), Cyril Mauclair (b) (c), Christophe Donnet (b) (c)
Affiliations : (a) Université de Lyon, Ecole Centrale de Lyon, Laboratoire de Tribologie et Dynamique des Systèmes (UMR 5513 CNRS), 36 avenue Guy de Collongues, 69134 Ecully cedex, France (b) Université de Lyon, Université de Saint-Etienne, Laboratoire Hubert Curien (UMR 5516 CNRS), 18 rue du Professeur Benoit Lauras, 42000 Saint-Etienne, France (c) GIE Manutech USD, 18 rue du Professeur Benoit Lauras, 42000 Saint-Etienne, France (d) Université de Haute-Alsace, Institut de Science des Matériaux de Mulhouse (UMR 7361 CNRS), 15 rue Jean Starcky, 68200 Mulhouse, France
Resume : The direction and motion of cells have a key role in many physiological processes, such as tissue morphogenesis, or embryonic development. These interactions are regulated by the chemical surface properties of the biomaterial and its surface topography. Topographical modifications of surfaces (µm and nm) are known to induce changes in cell shape and adhesion, thereby affecting cell behavior. The control of the cell contact guidance is very promising. Ko and al. have shown that the junction angles, can modulate the motion speed of cells without altering their directionality. Generally speaking, in its environment, the cell is not confronted to structures having strict corners, but to curved structures. Anselme and al. have studied that the influence of curved structures on cell behavior and Laser Induced Periodic Surface Structures (LIPSS) in static mode separately. In this work, the structures which were both curved and multi-scale patterned were designed and their influence on cell behavior was studied. TA6V is one of the most commonly used metallic alloys in biomedical applications. A femtosecond laser was used as a surface texturing technique in order to create multi-scale structures on the TA6V surface: material ablation (30µm) and generation of LIPPS (~600nm). The present work focused on stem and marcrophage cells motion (position, direction and speed) within multi-scaled structures to verify whether the LIPSS has a competitive or a complementary effect on cell movement.
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Nanostructures: Characterizations and Applications II : Schmidt F.-P.
Authors : O. Stephan, R. Bourrellier, L. Galvão Tizei, A. Gloter, N. Kawazaki, M. Kociak, A. Losquin, H. Lourenço Martins, K. March, S. Meuret, A. Tararan, M. Tencé, G. Tieri, A. Zobelli
Affiliations : Laboratoire de Physique des Solides, Bâtiment 510, UMR 8502, Université Paris-Sud,91405 Orsay Cedex, France; Morphological Research Laboratory, Toray Research Center Inc., Otsu, Shiga, 520-8567, Japan; Center for Nanophotonics, FOM Institute for Atomic and Molecular Physics (AMOLF), Kruislaan 407, 1098 SJ Amsterdam, The Netherlands
Resume : The field of electron energy-loss spectroscopy (EELS) in the scanning transmission electron microscope (STEM) has recently achieved successes linked with the development of aberration correctors, enabling atomically-resolved spectroscopy. Also, a new generation of monochromators is emerging, providing improvements in energy resolution and unprecedented access to low energy-loss ranges (optical and near IR spectral ranges). Similarly, recent progress in the collection of visible-range photons emitted by a sample has enabled novel cathodo-luminescence (CL) experiments in STEM. In addition, new ways of exploiting fast electron beams, including combining them with photon beams, have opened up the field of nano-optics, providing a high-spatial resolution alternative to conventional optical techniques. Examples will be given on the use of spatially-resolved core-level excitation signals for quantitative measurement of electron densities (charge accumulation)  or 2D electron gases at interfaces in oxide-based nanodevices. Developments in EELS and CL for reaching plasmon signatures down to the IR spectral range will be described, allowing the mapping of eigen modes in plasmonic nanostructures and a deep understanding of the physics of these excitation . New possibilities for exploring the link between a crystal structure (h-BN), its defects and its emission properties as revealed by nano-CL  and original quantum nano-optics experiments will be discussed .  M. Marinova et al, Nano Lett., 2015, 15 (4), 2533  A. Losquin, et al, Nano Lett., 2015, 15 (2), 1229  R. Bourrellier et al, ACS Photonics, 2014, 1 (9), 857  R. Bourrelier et al, to appear in Nanoletters.
Authors : Siew Li Tan,1,2 Yann Genuist,1,3 Henri Mariette,2,3 Nikos T. Pelekanos1,2,4*
Affiliations : 1: CEA, INAC, 17 rue des Martyrs, 38054 Grenoble cedex 9, France 2: Univ. Grenoble Alpes, F-38000 Grenoble, France 3: CNRS, Inst NEEL, F-38000 Grenoble, France 4: Materials Science & Technology Dept., Univ. of Crete and IESL/FORTH, 71110 Heraklion, Greece
Resume : Strained core-shell heterostructure nanowires are predicted to possess significant strain-induced lateral piezoelectric fields, which can provide a mechanism for efficient charge carrier separation and collection in a photovoltaic device. In this work, we investigate the material quality and optical properties of vertical GaAs/InGaAs core-shell nanowire arrays grown on n-type Si(111) substrate by molecular beam epitaxy using two approaches, namely self-assembled growth of randomly-positioned nanowires, and selective-area growth of periodic nanowire arrays. The self-assembled growth is performed on Si substrate covered with a controlled chemical oxide layer, while the selective-area growth is enabled by a nano-patterned thermal silicon dioxide mask on Si. Ga catalytic droplets are deposited in situ to initiate the growth of GaAs core nanowires via the well-known vapour-liquid-solid mechanism. We demonstrate how to improve compositional homogeneity in the InGaAs shell and successful p-type doping of the InGaAs shell to create a radial p-n or p-i-n junction device structure.
Authors : Janusz Sadowski, Slawomir Kret, Aloyzas Siusys, Anna Reszka, Tomasz Wojciechowski
Affiliations : Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, 02-668 Warszawa, Poland
Resume : Self-assembled hierarchical nanostructures comprising branched nanowires (NWs) are interesting for both fundamental research and potential applications. Even though the formation of branched NWs is quite easy to achieve, their controlled assembly is nontrivial and yet not well understood. Here we report on branched III-V semiconductor (GaAs) NWs grown by molecular beam epitaxy (MBE). The growth of NW branches can be achieved by a number of methods; we focus on two of them: (i) manipulation of the Au catalyst nano-droplet shape/position, (ii) deposition of secondary catalyst at the side-walls of primary NW trunk. In the first case we changed the composition and position of Au nandroplets by exposing already grown GaAs NWs first to As and then to In fluxes, at temperatures slightly lower than those applied to GaAs NWs growth; in the second approach the catalyst nandroplets/nanocrystals were formed at the sidewalls of primary GaAs NW trunks, and then generated the growth of NW branches. Two different types of secondary catalyst have been exploited (1) liquid phase Bi nano-droplets and (2) solid phase MnAs nanocrystals. The growth of branches proceeded then either in the vapor-liquid-solid (VLS), or vapor-solid-solid (VSS) NW growth mode; in the cases (1) and (2), respectively. We have observed significant differences in properties of branches generated on zinc-blende or wurtzite sections of primary GaAs NW trunks in both cases. The HRTEM, EDXS structural analysis is performed.
Authors : David Lehninger, Christian Röder, Larysa Khomenkova, Volker Klemm, David Rafaja, Johannes von Borany, Frank Schneider, and Johannes Heitmann
Affiliations : TU Bergakademie Freiberg, Institute of Applied Physics, Leipziger Str. 23, D-09599 Freiberg, Germany; TU Bergakademie Freiberg, Institute of Theoretical Physics, Leipziger Str. 23, D-09599 Freiberg, Germany; V. Lashkaryov Institute of Semiconductor Physics, 45 Pr. Nauky, Kyiv 03028, Ukraine; TU Bergakademie Freiberg, Institute of Material Science, Gustav-Zeuner-Str. 5, D-09599 Freiberg, Germany; TU Bergakademie Freiberg, Institute of Material Science, Gustav-Zeuner-Str. 5, D-09599 Freiberg, Germany; Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, D-01328 Dresden, Germany; TU Bergakademie Freiberg, Institute of Applied Physics, Leipziger Str. 23, D-09599 Freiberg, Germany; TU Bergakademie Freiberg, Institute of Applied Physics, Leipziger Str. 23, D-09599 Freiberg, Germany
Resume : Semiconductor or metallic nanocrystals embedded in dielectric matrices have attracted great attention over the last decade for many electronic and optoelectronic applications. In particular, Ge nanocrystals are discussed as charge storage nodes for nanocrystal based nonvolatile memory devices . However, synthesizing Ge nanocrystals in ZrO2 based high-k matrices a simultaneous crystallization of Ge and ZrO2 has been reported previously . In case of nonvolatile memories amorphous dielectrics are rather desired than multi-crystalline ones since grain boundaries act as paths for leakage currents supporting the discharging of the nanocrystals across the blocking oxide. In the present work, phase separation, nucleation, and crystallization processes in tantalum-containing ZrO2 (TaZrOx) and Ge-TaZrOx were investigated. For this purpose, 500 nm thick TaZrOx and Ge-TaZrOx films with various Ge-concentrations were deposited by rf magnetron sputtering. Size, shape, and spatial distribution of the Ge nanocrystals were determined by transmission electron microscopy. Varying the annealing temperature the crystallization processes were studied by X-ray diffraction and Raman scattering. In comparison to ZrO2 as dielectric matrix a temperature window between 650°C and 750°C can be be used in order to synthesize Ge nanocrystals within an amorphous TaZrOx matrix.  D. Lehninger et al.: Appl. Phys. Lett. 106, 023116 (2015)  S. Haas et al.: J. Appl. Phys. 113, 044303 (2013)
Authors : Thomas Riedl 1,2 , Jörg K.N. Lindner 1,2
Affiliations : 1. University of Paderborn, Department of Physics, Warburger Straße 100, 33098 Paderborn, Germany 2. Center for Optoelectronics and Photonics Paderborn (CeOPP), Warburger Straße 100, 33098 Paderborn, Germany
Resume : The technique of nanosphere lithography uses hexagonally close packed mono- or double layers of spheres as masks for site-controlled manipulation of the substrate surface. This enables a cost-effective patterning of large surface areas. For many applications of such patterned surfaces a narrow size distribution of features, i.e. of mask openings is essential. Therefore, the present contribution reports on an automated SEM image analysis of sphere monolayers and their interstices, with focus on the correlations between the sphere diameter, sphere position and interstice size distributions. In order to detect and evaluate the individual sphere diameters and positions iterative cross-correlation, multiple-angle intensity profiling, sphere edge point detection and fitting algorithms are applied, enabling a sphere detection efficiency of at least 99%. Moreover, the size of the interstices between the sphere triples are quantified by intensity thresholding. In this presentation we analyze how the sphere size distributions as well as the sphere position variations contribute to the observed interstice size variations of polystyrene nanosphere monolayers for average sphere diameters in the range between 220 nm and 618 nm. The findings are corroborated by simple geometric models, which use the fitted sphere diameters and positions as input data.
Nanostructures: Synthesis and Applications II : Jehl X.
Authors : Adam Gali
Affiliations : Wigner Research Centre for Physics, Hungarian Academy of Sciences; Department of Atomic Physics, Budapest University of Technology and Economics
Resume : The magneto-optical and vibration properties of nanostructures are determined by density functional theory, time-dependent density functional theory and many-body perturbation theory. The results demonstrate the predictive power of these theories by showing that the complex interplay of defects inside the nanoparticles, surface termination and the size of nanoparticles set the basic properties of semiconductor nanoparticles. These theories are applied to design nanoparticles for desired applications. Particularly, we will show examples on single photon emitters for quantum technologies, fluorescent nanoparticles for in vivo biomaging where the corresponding successful experiments were driven and understood by theory.
Authors : Viktoryia Zolatanosha, Dirk Reuter
Affiliations : Department of Physics, University of Paderborn
Resume : To control the exact position of semiconductor nanostructures, especially quantum dots (QDs), is important for incorporating these nanostructures into novel semiconductor devices. Although self-assembled growth can produce very high quality QDs either by strained layer or droplet epitaxy, the position of the dot formation is random. An approach to overcome this limitation is to use a combination of self-assembly and selective area epitaxy (SAE). SAE is a kind of template method, which allows for laterally patterned material deposition. By making the size of the area equal or smaller to the mean distance in self-assembled growth, it should be possible to position of a single nanostructure with high accuracy. In this contribution, we present a shadow mask approach for SAE in the InAs/GaAs-system. The mechanical mask is realized on a SiN-membrane base by employing nanofabrication technology allowing for hole diameters down to 100 nm. The membrane is fabricated from a Si-wafer covered with 100 nm Si3N4 by anisotropic chemical etching of Si(100) applying KOH. The membrane itself is patterned by electron beam lithography and reactive ion etching. The tests show that the mask is fully compatible with ultra-high-vacuum and can withstand temperatures up to 850°C, i. e., it is compatible with our molecular beam epitaxy process. GaAs layers, which are deposited on the top side of the mask, result in a reduction of the hole size in the membrane and they can be re-evaporated without damaging the mask. The first deposition tests through the mask show selected area deposition of Ga droplets, which can be converted to GaAs QDs.
Authors : Peter Seidel, Sascha Pomp, Ahmed Ghalgaoui, Martin Sterrer
Affiliations : University of Graz, Institute of Physics
Resume : Single-crystalline oxide thin films supported by metals are a well-accepted class of model system for studying fundamental aspects of oxide surface and thin oxide layer chemistry and physics . In the present contribution, we report on our efforts to expand this model approach to electrochemical studies on well-ordered oxide surfaces. Single-crystalline FeO(111) and Fe3O4(111) films were grown under ultra-high vacuum (UHV) conditions on a Pt(111) substrate and subsequently transferred into air or brought into contact with various aqueous solutions . We have tested the stability of the oxide layers in these environments and characterized their electrochemical properties by cyclic voltammetry. The surface morphology and potential-dependent surface structure changes were investigated in-situ by electrochemical scanning tunneling microscopy (EC-STM) and potential-controlled sum frequency generation spectroscopy (EC-SFG). The influences of ionic strength and pH value on the oxide-water interface were examined. Finally, two different organic compounds (Catechol and Aminophthalic acid) were deposited in UHV and from solution and were investigated by electrochemical and UHV methods.  W. Weiss, W. Ranke, Prog. Surf. Sci. 2002, 70, 1-151.  H.-F. Wang, H. Ariga, R. Dowler, M. Sterrer, H.-J. Freund, J. Catal. 2012, 286, 1-5.
Authors : A. Gómez-Núñez(1), C. López(2), P. Roura(3), M. Font-Bardia(4), A. Vilà(1)
Affiliations : (1)Departament d’Enginyeries: Electrònica, Universitat de Barcelona, Martí i Franquès 1, 08028-Barcelona, Spain. ; (2)Departament de Química Orgànica i Inorgànica, Universitat de Barcelona, Martí i Franquès 1, 08028-Barcelona, Spain. ; (3)Departament de Física, Universitat de Girona, Campus Montilivi, Edif. PII, E-17071-Girona, Spain. ; (4)Unitat DRX (CCiT-Universitat de Barcelona), Solé i Sabarís 1-3, 08028-Barcelona, Spain.
Resume : Heteropolynuclear (HPN) organometallic compounds (OMC) are attracting great interest since long ago. In these products, several proximal metals with various oxidation numbers and spin states coexist in different crystalline environments. The mutual interaction between these ions may modify their stability or catalytic and biological activity, and opens a bunch of applications with potential impact in Materials Sciences (as precursors for new materials) and new technologies (as single molecular magnets). Due to the increasing interest of the incorporation of Fe(II) or (III) in polymetallic arrays and previous experience in Zn(II) polymers (E-MRS Fall 2015), the synthesis of new HPN derivatives with Zn and Fe(II) or (III) has become one promising challenge. Here we present the synthesis and characterization of a new decametallic (Fe6Zn4) OMC prepared at room temperature. Its crystalline structure confirmed the presence of molecules where a 4 Zn(II), sited on the vertex of a trigonal pyramid, form the internal core and the Fe(II) ions are peripherally distributed and connected to the Zn(II) through O-donor ligands. As a consequence of this arrangement of metal ions, the molecular shape resembles a sphere (ca. 16 Å diameter). This type of metal ions distribution in the molecule has no precedent. Since the decomposition products depend on the particular atmosphere, further studies concerning its thermal stability in N2 and air and its potential applications will be also presented.
Authors : E. Cara (1,2), F. Ferrarese Lupi (1), M. Dialameh (1,2), M. Fretto (1), N. De Leo (1), L. Boarino (1)
Affiliations : (1) Istituto Nazionale di Ricerca Metrologia (INRIM), Strada delle Cacce 91, 10135 Turin, Italy (2) Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129, Turin, Italy
Resume : Nanosphere lithography (NSL) attracted growing interest in nanotechnology for the realization of well-ordered and regular patterns at nanometric scale. NLS is indeed an inexpensive and versatile method that has found many practical applications such as the fabrication of nanowires, SERS substrates, charge trap flash memories, optical devices and LEDs surface texturing. However, one of the main factors limiting the use of NSL in large-scale lithography is the inhomogeneity of the self-assembled layer after spin coating process. A possible solution to this problem is the use of directed self-assembly of the nanospheres inside topographically defined patterns. In facts, this approach is able to combine the advantages of both the top-down and bottom-up approaches. In this work we systematically investigated the ordering process of polystyrene (PS) nanospheres confined inside periodic patterns with different geometries (hexagonal, linear and circular) defined by means of laser-writer lithography. The confinement of the PS nanospheres has been studied in both soft graphoepitaxy configuration (directly inside an optical resist) and hard graphoepitaxy configuration (SiO2 hard mask obtained by Reactive Ion Etching). As a result of this study, we have been able to extend the long range ordering of the PS nanospheres to areas as large as some squared millimetres.
Nanoelectronic Applications : Gali A.
Authors : R. Maurand1, X. Jehl1 D. Kotekar-Patil1, A. Corna1, H. Bohuslavskyi1, R. Lavieville2, L. Hutin2, S. Barraud2, M. Vinet2, M. Sanquer1 and S. De Franceschi1
Affiliations : 1. CEA-Grenoble, INAC-PHELIQS and Université Grenoble Alpes 2. CEA-Grenoble, LETI-Minatec and Université Grenoble Alpes
Resume : State-of-the-art microelectronics technology produces transistors with dimensions of the order of ten nanometers. At this scale and at low temperature such devices behave as quantum dots in which a single spin can be isolated. Hole spins in silicon represent a promising direction because of limited hyperfine interaction and potentially fast manipulation. Therefore a route towards solid-state quantum computation could be to ``quantumize`` already integrated silicon bits instead of trying to scale-up existing quantum bits made with different technologies. We will present a silicon CMOS nanowire transistor operated as a hole spin qubit. Our devices are similar to industrial silicon-on-insulator transistors except that they feature two gates in series to define a double quantum dot. A microwave signal applied to one gate induces a hole spin resonance in the first dot detected via Pauli spin blockade thanks to the second dot. Pulsing the device from spin blockade to Coulomb blockade, we demonstrate coherent manipulation with Rabi frequencies as high as 80MHz with an inhomogeneous dephasing time T2*~60ns, while spin echo reveals a coherence time T2echo~250ns. Our experiment shows that industry-standard CMOS transistors can be operated as hole spin qubits with an electrical control providing fast rotation and single gate control.
Authors : K.-H. Heinig (1), K.-H. Stegemann (2), J. v. Borany (1), S. Facsko (1), G. Hlavacek (1), R. Hübner (1), L. Bischoff (1), W. Möller (1), T. Prüfer (1), X. Xu (1)
Affiliations : (1) Research Center Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Germany (2) X-FAB Dresden GmbH & Co. KG, 01109 Dresden, Grenzstrasse 28, Germany
Resume : Top-down processes in microelectronics allow the fabrication of structures down to ~10 nm. However, such structures are not small enough to operate at room temperature (RT) quantum devices with switching mechanisms different from CMOS. E.g., the extremely low-power device Single Electron Transistor (SET) works at RT only if the size of the quantum dot is below 5nm, and if the tunnel distances through SiO2 are a few nm only. Here we present a directed self-assembly process of a 2-3 nm small single Si dot located in the middle of a SiO2 layer with distances of ~2 nm to the upper and lower Si. The self-assembly occurs by phase separation of metastable SiOx during heat treatment. The self-assembly becomes directed by constraining and shaping the SiOx volume in such a manner that a single Si quantum dot in the requested position forms. The SiOx is fabricated by collisional mixing of Si atoms from above and below in the SiO2 layer. Two methods to form a local, constrained volume of SiOx are presented: (i) A large-area Si/SiO2/Si layer stack is irradiated with a 2nm narrow energetic Ne beam in a Helium Ion Microscope (HIM), which results in a ~10nm disk of SiOx in the buried SiO2 layer. (ii) Si pillars (<20nm) with an embedded SiO2 layer are irradiated with a broad beam of energetic Si ions. Method (ii) will be used to fabricate SETs in CMOS technology. This work has been funded by the European Union's Horizon 2020 research and innovation program under grant agreement No 688072.
Authors : Stefan Facsko, Xin Ou, Martin Engler
Affiliations : Ion Beam Center, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany; State Key Laboratory of Functional Material for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; Ion Beam Center, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany;
Resume : Low energy ion irradiation drives surfaces out of equilibrium by continuous atomic displacements in the sub-surface. At room temperature the accumulation of the created defects leads to surface amorphization and self-organized ripple patterns perpendicular or parallel to the ion beam direction are formed for incidence angles higher than 50°. At temperatures higher than the recrystallization temperature, however, all defects in the sub-surface region are dynamically annealed and the surface remains crystalline. In this regime, ion irradiation creates vacancies and ad-atoms on the crystalline surface due to sputtering and dislocations. The surfaces morphology is now determined by the kinetics of the mobile surface species. Due to the Ehrlich-Schwoebel barrier, i.e. an additional barrier for crossing terrace steps, 3D structures are created in a “reverse epitaxy” process . We will present different kinds of self-organized patterns on crystalline surfaces induced by ion irradiation at elevated temperatures. Depending on the crystalline structure and the surface orientation regular patterns of inverse pyramids with three-fold, four-fold, or six-fold symmetry are observed. Furthermore, on III-V semiconductors with zinc-blende structure extremely regular periodic groove patterns with crystalline facets are produced . Such periodic patterns can be used as templates for the deposition of nanostructured thin films with effective medium properties determined by the morphology, e.g. exhibiting a strong anisotropy.  X. Ou, A. Keller, M. Helm, J. Fassbender, and S. Facsko, Phys. Rev. Lett. 111, 016101 (2013).  X. Ou, K.-H. Heinig, R. Hübner, J. Grenzer, X. Wang, M. Helm, J. Fassbender, and S. Facsko, Nanoscale 7, 18928 (2015).
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