47 results on '"Martin Foldyna"'
Search Results
2. Evolution of Cu-In Catalyst Nanoparticles under Hydrogen Plasma Treatment and Silicon Nanowire Growth Conditions
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Weixi Wang, Éric Ngo, Pavel Bulkin, Zhengyu Zhang, Martin Foldyna, Pere Roca i Cabarrocas, Erik V. Johnson, and Jean-Luc Maurice
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Cu-In nanoparticle ,plasma treatment ,silicon nanowire ,PECVD ,TEM ,Chemistry ,QD1-999 - Abstract
We report silicon nanowire (SiNW) growth with a novel Cu-In bimetallic catalyst using a plasma-enhanced chemical vapor deposition (PECVD) method. We study the structure of the catalyst nanoparticles (NPs) throughout a two-step process that includes a hydrogen plasma pre-treatment at 200 °C and the SiNW growth itself in a hydrogen-silane plasma at 420 °C. We show that the H2-plasma induces a coalescence of the Cu-rich cores of as-deposited thermally evaporated NPs that does not occur when the same annealing is applied without plasma. The SiNW growth process at 420 °C induces a phase transformation of the catalyst cores to Cu7In3; while a hydrogen plasma treatment at 420 °C without silane can lead to the formation of the Cu11In9 phase. In situ transmission electron microscopy experiments show that the SiNWs synthesis with Cu-In bimetallic catalyst NPs follows an essentially vapor-solid–solid process. By adjusting the catalyst composition, we manage to obtain small-diameter SiNWs—below 10 nm—among which we observe the metastable hexagonal diamond phase of Si, which is predicted to have a direct bandgap.
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- 2023
- Full Text
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3. Optimization of the optical coupling in nanowire-based integrated photonic platforms by FDTD simulation
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Nan Guan, Andrey Babichev, Martin Foldyna, Dmitry Denisov, François H. Julien, and Maria Tchernycheva
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FDTD modeling ,nanowire LED ,nitride nanowires ,photonic integrated circuit ,photonic platform ,SiN/InGaN co-integration ,visible light communication ,Technology ,Chemical technology ,TP1-1185 ,Science ,Physics ,QC1-999 - Abstract
The optimized design of a photonic platform based on a nanowire light emitting diode (LED) and a nanowire photodetector connected with a waveguide is proposed. The light coupling efficiency from the LED to the detector is optimized as a function of the geometrical parameters of the system using the finite difference time domain simulation tool Lumerical. Starting from a design reported in the literature with a coupling efficiency of only 8.7%, we propose an optimized photonic platform with efficiency reaching 65.5%.
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- 2018
- Full Text
- View/download PDF
4. Optical Study and Experimental Realization of Nanostructured Back Reflectors with Reduced Parasitic Losses for Silicon Thin Film Solar Cells
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Zeyu Li, Rusli E, Chenjin Lu, Ari Bimo Prakoso, Martin Foldyna, Rasha Khoury, Pavel Bulkin, Junkang Wang, Wanghua Chen, Erik Johnson, and Pere i Roca Cabarrocas
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light trapping ,silicon thin film ,photovoltaics ,polystyrene sphere assisted lithography ,nanostructured back reflectors ,Chemistry ,QD1-999 - Abstract
We study light trapping and parasitic losses in hydrogenated amorphous silicon thin film solar cells fabricated by plasma-enhanced chemical vapor deposition on nanostructured back reflectors. The back reflectors are patterned using polystyrene assisted lithography. By using O2 plasma etching of the polystyrene spheres, we managed to fabricate hexagonal nanostructured back reflectors. With the help of rigorous modeling, we study the parasitic losses in different back reflectors, non-active layers, and last but not least the light enhancement effect in the silicon absorber layer. Moreover, simulation results have been checked against experimental data. We have demonstrated hexagonal nanostructured amorphous silicon thin film solar cells with a power conversion efficiency of 7.7% and around 34.7% enhancement of the short-circuit current density, compared with planar amorphous silicon thin film solar cells.
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- 2018
- Full Text
- View/download PDF
5. Liquid-assisted vapor-solid-solid silicon nanowire growth mechanism revealed by in situ TEM when using Cu-Sn bimetallic catalysts
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Pere Roca i Cabarrocas, Pavel Bulkin, Jean-Luc Maurice, Martin Foldyna, Weixi Wang, Ileana Florea, Eric Ngo, Institut de Chimie et des Matériaux Paris-Est (ICMPE), Institut de Chimie du CNRS (INC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), ANR-17-CE09-0011,HexaNW,Croissance vapeur-liquide-solide de nanofils de silicium de phase hexagonale diamant(2017), and ANR-10-EQPX-0050,TEMPOS,Microscopie electronique en transmission sur le plateau Palaiseau Orsay Saclay(2010)
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In situ ,Materials science ,Silicon ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,7. Clean energy ,01 natural sciences ,Silane ,Dissociation (chemistry) ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Catalysis ,chemistry.chemical_compound ,General Energy ,Chemical engineering ,chemistry ,Transmission electron microscopy ,0103 physical sciences ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Molecule ,Physical and Theoretical Chemistry ,010306 general physics ,0210 nano-technology ,Bimetallic strip - Abstract
International audience; The vapor-liquid-solid (VLS) and vapor-solid-solid (VSS) growth mechanisms are widely used to obtain silicon nanowires. In this paper, we report on a hybrid method based on the use of a dual-phase catalyst made of liquid Sn and solid Cu 3 Si, which results in a liquid-assisted VSS (LA-VSS) mechanism. The silicon atoms are brought by atomic hydrogen-assisted dissociation of silane molecules. We observe the growth in situ, in the transmission electron microscope, at
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- 2021
6. Tin reduction from fluorine doped tin oxide for silicon nanowire-based solar energy harvesting and storage
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Lukas, Halagacka, primary, Zuzana, Gelnarova, additional, Mutaz, Al-Ghzaiwat, additional, Ileana, Florea, additional, Jiri, Hornicek, additional, Kamil, Postava, additional, and Martin, Foldyna, additional
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- 2021
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7. Plasma-Enhanced Chemical Vapor Deposition in a Transmission Electron Microscope?
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Jean-Luc Maurice, Pavel Bulkin, Éric Ngo, Weixi Wang, Pere Roca i Cabarrocas, Martin Foldyna, and Ileana Florea
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Instrumentation - Published
- 2021
8. Improvement of carrier collection in Si/a-Si:H nanowire solar cells by using hybrid ITO/silver nanowires contacts
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Martin Foldyna, Tiphaine Mathieu-Pennober, Shan-Ting Zhang, François H. Julien, Nathanaelle Schneider, Maria Tchernycheva, Centre de Nanosciences et de Nanotechnologies (C2N), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), and Institut Photovoltaïque d’Ile-de-France (ITE) (IPVF)
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Amorphous silicon ,Materials science ,Nanowire ,Bioengineering ,02 engineering and technology ,Chemical vapor deposition ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,law.invention ,[SPI.MAT]Engineering Sciences [physics]/Materials ,chemistry.chemical_compound ,law ,Solar cell ,General Materials Science ,Electrical and Electronic Engineering ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,Equivalent series resistance ,business.industry ,Mechanical Engineering ,Energy conversion efficiency ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Mechanics of Materials ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Optoelectronics ,Charge carrier ,0210 nano-technology ,business ,Layer (electronics) - Abstract
International audience; Optoelectronic devices based on high aspect ratio nanowires bring new challenges for transparent electrodes, which can be well addressed by using hybrid structures. Here we demonstrate that a composite contact to radial junction nanowire solar cells made of a thin indium-tin oxide (ITO) layer and silver nanowires greatly improves the collection of charge carriers as compared to a single thick ITO layer by reducing the series resistance losses while improving the transparency. The optimization is performed on p-in solar cells comprising of dense non-vertical nanowires with a p-doped c-Si core and an ultra-thin a-Si:H absorption layer grown by plasma-enhanced chemical vapor deposition on glass substrates. The optimal hybrid contact developed in this work is demonstrated to increase the solar cell conversion efficiency from 4.3% to 6.6%.
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- 2020
9. ALD of ZnO:Ti: Growth Mechanism and Application as an Efficient Transparent Conductive Oxide in Silicon Nanowire Solar Cells
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Nathanaelle Schneider, Frédérique Donsanti, Shan-Ting Zhang, Tiphaine Mathieu-Pennober, Damien Coutancier, Simone Bernardini, Olivier Fournier, Martin Foldyna, Maria Tchernycheva, Institut Photovoltaïque d’Ile-de-France (UMR) (IPVF), École polytechnique (X)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-TOTAL FINA ELF-EDF (EDF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Photovoltaïque d’Ile-de-France (ITE) (IPVF)-Air Liquide [Siège Social], UFR des Sciences et Technologies, Université de La Réunion (UR), EDF (EDF), Institut d'électronique fondamentale (IEF), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), and École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)
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Materials science ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Atomic layer deposition ,Crystallinity ,Etching (microfabrication) ,[CHIM]Chemical Sciences ,General Materials Science ,Thin film ,Metrics & More Article Recommendations atomic layer deposition ,QCM studies ,Transparent conducting film ,ZnO:Ti ,business.industry ,Quartz crystal microbalance ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Indium tin oxide ,chemistry ,TCO ,silicon nanowire solar cells ,Optoelectronics ,0210 nano-technology ,business ,Titanium ,n-type - Abstract
International audience; In the quest for the replacement of indium tin oxide (ITO), Ti-doped zinc oxide (TZO) films have been synthesized by atomic layer deposition (ALD) and applied as an n-type transparent conductive oxide (TCO). TZO thin films were obtained from titanium (IV) i-propoxide (TTIP), diethyl zinc, and water by introducing TiO 2 growth cycle in a ZnO matrix. Process parameters such as the order of precursor introduction, the cycle ratio, and the film thickness were optimized. The as-deposited films were analyzed for their surface morphology, elemental stoichiometry, optoelectronic properties, and crystallinity using a variety of characterization techniques. The growth mechanism was investigated for the first time by in situ quartz crystal microbalance measurements. It evidenced different insertion modes of titanium depending on the precursor introduction, as well as the etching of Zn−Et surface groups by TTIP. Resistivity as low as 1.2 × 10 −3 Ω cm and transmittance >80% in the visible range were obtained for 72-nm-thick films. Finally, the first application of ALD-TZO as TCO was reported. TZO films were successfully implemented as top electrodes in silicon nanowire solar cells. The unique properties of TZO combined with conformal coverage realized by the ALD technique make it possible for the cell to show almost flat external quantum efficiency (EQE) response, surpassing the bell-like EQE curve seen in devices with a sputtered ITO top electrode.
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- 2020
10. Visualizing the effects of plasma-generated H atoms in situ in a transmission electron microscope
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Jean-Luc Maurice, Pavel Bulkin, Éric Ngo, Weixi Wang, Martin Foldyna, Ileana Florea, Pere Roca i Cabarrocas, Romuald Béjaud, Olivier Hardouin Duparc, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Solides Irradiés (LSI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Défauts, Désordre et Structuration de la Matière (DDSM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), ANR-10-EQPX-0050,TEMPOS,Microscopie electronique en transmission sur le plateau Palaiseau Orsay Saclay(2010), ANR-17-CE09-0011,HexaNW,Croissance vapeur-liquide-solide de nanofils de silicium de phase hexagonale diamant(2017), and LSI - Théorie de la science des matériaux (TSM)
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[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Condensed Matter Physics ,Instrumentation ,Electronic, Optical and Magnetic Materials - Abstract
The radicals and atoms generated by a plasma have the effect, among others, of changing the surface energies of materials, which allows one to prepare nano-objects that would not stabilise in other conditions. This is the case of the Sn catalysed silicon nanowires (NWs) we present in this paper: without plasma, the liquid Sn at the top of NWs is unstable (because Sn naturally wets the Si) so that no growth is allowed, while in presence of the H atoms generated by the plasma, the balance of surface energies is drastically changed; the Sn droplet stabilises and can be used efficiently by the vapour-liquid-solid (VLS) mechanism of growth. Thus, if one wants to study the growth mechanisms of such NWs in situ in the transmission electron microscope (TEM), one has to adapt a plasma system on the TEM. This is precisely what was done at École polytechnique on the NanoMAX environmental TEM. The paper reports on the plasma effects, on the catalyst and on NW growth, recorded in situ in real time, at atomic resolution. The results are discussed in the light of density functional calculations of bare and hydrogenated Si surface energies.
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- 2022
11. Optimization of the optical coupling in nanowire-based integrated photonic platforms by FDTD simulation
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Martin Foldyna, Maria Tchernycheva, François H. Julien, D. V. Denisov, A. V. Babichev, Nan Guan, Centre de Nanosciences et de Nanotechnologies [Orsay] (C2N), Université Paris-Sud - Paris 11 (UP11)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), National Research University of Information Technologies, Mechanics and Optics [St. Petersburg] (ITMO), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), and Saint Petersburg Electrotechnical University 'LETI'
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visible light communication ,Materials science ,nanowire LED ,Nanowire ,General Physics and Astronomy ,Photodetector ,Physics::Optics ,02 engineering and technology ,lcsh:Chemical technology ,7. Clean energy ,01 natural sciences ,Waveguide (optics) ,lcsh:Technology ,Full Research Paper ,law.invention ,010309 optics ,law ,FDTD modeling ,0103 physical sciences ,Nanotechnology ,General Materials Science ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,photonic integrated circuit ,lcsh:Science ,photonic platform ,ComputingMilieux_MISCELLANEOUS ,SiN/InGaN co-integration ,[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] ,business.industry ,lcsh:T ,Detector ,Photonic integrated circuit ,Finite-difference time-domain method ,nitride nanowires ,021001 nanoscience & nanotechnology ,lcsh:QC1-999 ,Nanoscience ,Optoelectronics ,lcsh:Q ,Photonics ,0210 nano-technology ,business ,lcsh:Physics ,Light-emitting diode - Abstract
The optimized design of a photonic platform based on a nanowire light emitting diode (LED) and a nanowire photodetector connected with a waveguide is proposed. The light coupling efficiency from the LED to the detector is optimized as a function of the geometrical parameters of the system using the finite difference time domain simulation tool Lumerical. Starting from a design reported in the literature with a coupling efficiency of only 8.7%, we propose an optimized photonic platform with efficiency reaching 65.5%.
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- 2018
12. Nanostructured back reflectors produced using polystyrene assisted lithography for enhanced light trapping in silicon thin film solar cells
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Wanghua Chen, Ari Bimo Prakoso, Pere Roca i Cabarrocas, Zeyu Li, Martin Foldyna, Junkang Wang, Chenjin Lu, E. Rusli, School of Electrical and Electronic Engineering, and Nanoelectronics Centre of Excellence
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Amorphous silicon ,Materials science ,02 engineering and technology ,Trapping ,Chemical vapor deposition ,010402 general chemistry ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,law ,Solar cell ,General Materials Science ,Lithography ,Light Trapping ,Renewable Energy, Sustainability and the Environment ,business.industry ,Energy conversion efficiency ,Silicon Thin Film ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Electrical and electronic engineering [Engineering] ,Optoelectronics ,Polystyrene ,Current (fluid) ,0210 nano-technology ,business - Abstract
We study light trapping in hydrogenated amorphous silicon thin film solar cells fabricated by plasma-enhanced chemical vapor deposition on various nanostructured back reflectors. The back reflectors are patterned using polystyrene assisted lithography. We have investigated the correlation between the back reflector optical properties and the corresponding solar cell performance. We have introduced double size polystyrene sphere patterned back reflectors and have provided experimental evidence for improved light trapping performance compared to single size polystyrene sphere patterned back reflectors. We have achieved high performing nanostructured amorphous silicon solar cells with an initial power conversion efficiency of 7.53% and over 20% enhancement of the short-circuit current compared with the reference flat solar cell.
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- 2018
13. Room Temperature Growth of Silica Nanowires on Top of Ultrathin Si Nanowires Synthesized with Sn‐Cu Bimetallic Seeds
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Ileana Florea, Eric Ngo, Jean-Luc Maurice, Pere Roca i Cabarrocas, Weixi Wang, Martin Foldyna, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), ANR-17-CE09-0011,HexaNW,Croissance vapeur-liquide-solide de nanofils de silicium de phase hexagonale diamant(2017), and ANR-10-EQPX-0050,TEMPOS,Microscopie electronique en transmission sur le plateau Palaiseau Orsay Saclay(2010)
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Materials science ,Nanowire ,02 engineering and technology ,Surfaces and Interfaces ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Chemical engineering ,Transmission electron microscopy ,Plasma-enhanced chemical vapor deposition ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Materials Chemistry ,Electrical and Electronic Engineering ,0210 nano-technology ,Silicon nanowires ,Bimetallic strip ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2021
14. Silicon Nanowire Solar Cells with μc‐Si:H Absorbers for Radial Junction Devices
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Isabelle Maurin, Pere Roca i Cabarrocas, Jean-Paul Kleider, Thierry Gacoin, Alvarez José, Letian Dai, Martin Foldyna, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Génie électrique et électronique de Paris (GeePs), CentraleSupélec-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Matériaux, Rayonnements, Structure (MRS), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), and Laboratoire de physique de la matière condensée (LPMC)
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Materials science ,02 engineering and technology ,7. Clean energy ,01 natural sciences ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Plasma-enhanced chemical vapor deposition ,0103 physical sciences ,Materials Chemistry ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,[INFO.INFO-BT]Computer Science [cs]/Biotechnology ,Electrical and Electronic Engineering ,Silicon nanowires ,ComputingMilieux_MISCELLANEOUS ,010302 applied physics ,business.industry ,[SPI.NRJ]Engineering Sciences [physics]/Electric power ,Surfaces and Interfaces ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Optoelectronics ,0210 nano-technology ,business - Abstract
International audience
- Published
- 2021
15. Low-cost high-efficiency system for solar-driven conversion of CO
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Tran Ngoc, Huan, Daniel Alves, Dalla Corte, Sarah, Lamaison, Dilan, Karapinar, Lukas, Lutz, Nicolas, Menguy, Martin, Foldyna, Silver-Hamill, Turren-Cruz, Anders, Hagfeldt, Federico, Bella, Marc, Fontecave, and Victor, Mougel
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Commentaries - Abstract
Conversion of carbon dioxide into hydrocarbons using solar energy is an attractive strategy for storing such a renewable source of energy into the form of chemical energy (a fuel). This can be achieved in a system coupling a photovoltaic (PV) cell to an electrochemical cell (EC) for CO
- Published
- 2019
16. Low-cost high-efficiency system for solar-driven conversion of CO 2 to hydrocarbons
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Lukas Lutz, Anders Hagfeldt, Sarah Lamaison, Nicolas Menguy, Tran Ngoc Huan, Marc Fontecave, Daniel Alves Dalla Corte, Silver-Hamill Turren-Cruz, Dilan Karapinar, Victor Mougel, Martin Foldyna, Federico Bella, Collège de France - Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Chimie du solide et de l'énergie (CSE), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratory of Photomolecular Science (LSPM), Ecole Polytechnique Fédérale de Lausanne (EPFL), and Chaire Chimie des processus biologiques
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Electrocatalysis ,PV–EC ,CO2 reduction ,Electrolyzer ,Copper dendrites ,Materials science ,copper dendrites ,electrocatalysis ,electrolyzer ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,Electrochemical cell ,law.invention ,pv-ec ,law ,evolution ,ethylene ,[CHIM]Chemical Sciences ,Process engineering ,Multidisciplinary ,copper-oxide electrocatalyst ,catalysis ,business.industry ,Photovoltaic system ,021001 nanoscience & nanotechnology ,Solar energy ,electroreduction ,Cathode ,0104 chemical sciences ,Renewable energy ,Anode ,Chemical energy ,water oxidation ,13. Climate action ,cells ,0210 nano-technology ,business ,Efficient energy use - Abstract
Conversion of carbon dioxide into hydrocarbons using solar energy is an attractive strategy for storing such a renewable source of energy into the form of chemical energy (a fuel). This can be achieved in a system coupling a photovoltaic (PV) cell to an electrochemical cell (EC) for CO2 reduction. To be beneficial and applicable, such a system should use low-cost and easily processable photovoltaic cells and display minimal energy losses associated with the catalysts at the anode and cathode and with the electrolyzer device. In this work, we have considered all of these parameters altogether to set up a reference PV–EC system for CO2 reduction to hydrocarbons. By using the same original and efficient Cu-based catalysts at both electrodes of the electrolyzer, and by minimizing all possible energy losses associated with the electrolyzer device, we have achieved CO2 reduction to ethylene and ethane with a 21% energy efficiency. Coupled with a state-of-the-art, low-cost perovskite photovoltaic minimodule, this system reaches a 2.3% solar-to-hydrocarbon efficiency, setting a benchmark for an inexpensive all–earth-abundant PV–EC system. ISSN:0027-8424 ISSN:1091-6490
- Published
- 2019
17. Flexible Photodiodes Based on Nitride Core/Shell p–n Junction Nanowires
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Xing Dai, Nan Guan, Eric Gautier, Fabienne Michelini, Valerio Piazza, Maria Tchernycheva, H. Zhang, Vladimir Neplokh, Joël Eymery, Agnes Messanvi, Marc Bescond, Nicolas Cavassilas, Martin Vallo, A. V. Babichev, Christophe Durand, Martin Foldyna, François H. Julien, Catherine Bougerol, Institut d'électronique fondamentale (IEF), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Nanophysique et Semiconducteurs (NPSC), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Nanophysique et Semiconducteurs (NEEL - NPSC), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Nanostructures et Rayonnement Synchrotron (NRS ), Modélisation et Exploration des Matériaux (MEM), ANR-11-LABX-0014,GANEX,Réseau national sur GaN(2011), ANR-10-LABX-0035,Nano-Saclay,Paris-Saclay multidisciplinary Nano-Lab(2010), ANR-14-CE26-0020,PLATOFIL,PLAteforme phoTOnique à base de nanoFILs(2014), European Project: 639052,NanoHarvest, Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
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Materials science ,Nanowire ,02 engineering and technology ,Nitride ,010402 general chemistry ,01 natural sciences ,[SPI.MAT]Engineering Sciences [physics]/Materials ,law.invention ,Responsivity ,law ,General Materials Science ,Quantum well ,InGaN ,business.industry ,Photoconductivity ,Detector ,flexible photodiode ,nitride nanowires ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Photodiode ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Optoelectronics ,self-powered photodetectors ,core/shell p−n junction ,0210 nano-technology ,business ,p–n junction ,Research Article - Abstract
International audience; A flexible nitride p-n photodiode is demonstrated. The device consists of a composite nanowire/polymer membrane trans- ferred onto a flexible substrate. The active element for light sensing is a vertical array of core/shell p−n junction nanowires containing InGaN/ GaN quantum wells grown by MOVPE. Electron/hole generation and transport in core/shell nanowires are modeled within nonequilibrium Green function formalism showing a good agreement with experimental results. Fully flexible transparent contacts based on a silver nanowire network are used for device fabrication, which allows bending the detector to a few millimeter curvature radius without damage. The detector shows a photoresponse at wavelengths shorter than 430 nm with a peak responsivity of 0.096 A/W at 370 nm under zero bias. The operation speed for a 0.3 × 0.3 cm2 detector patch was tested between 4 Hz and 2 kHz. The −3 dB cutoff was found to be ∼35 Hz, which is faster than the operation speed for typical photoconductive detectors and which is compatible with UV monitoring applications.
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- 2016
18. Performance Analysis of AlxGa1-xAs/epi-Si(Ge) Tandem Solar Cells: A Simulation Study
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Martin Foldyna, José Alvarez, Romain Cariou, P. Roca i Cabarrocas, Gwenaëlle Hamon, Jean-Paul Kleider, Jean Decobert, Raphaël Lachaume, Laboratoire Génie électrique et électronique de Paris (GeePs), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Alcatel-Thalès III-V lab (III-V Lab), THALES [France]-ALCATEL, ANR-13-PRGE-0009,IMPETUS,Multi-jonctions innovantes combinant MOVPE et épitaxie à basse température pour le solaire(2013), and THALES-ALCATEL
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Materials science ,Silicon ,chemistry.chemical_element ,02 engineering and technology ,Substrate (electronics) ,Quantum dot solar cell ,Epitaxy ,7. Clean energy ,01 natural sciences ,Polymer solar cell ,[SPI.MAT]Engineering Sciences [physics]/Materials ,law.invention ,Optics ,Energy(all) ,law ,Plasma-enhanced chemical vapor deposition ,0103 physical sciences ,Solar cell ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,silicon on III-V ,010302 applied physics ,Tandem ,business.industry ,III-V on silicon ,modeling ,simulation ,021001 nanoscience & nanotechnology ,[SPI.TRON]Engineering Sciences [physics]/Electronics ,chemistry ,Optoelectronics ,tandem solar cells ,0210 nano-technology ,business - Abstract
International audience; A new strategy for the development of III-V/Si tandem solar cells has recently been proposed consisting in low temperature PECVD epitaxy of silicon or silicon-germanium on gallium-arsenide. This paper thus gives first insights about theoretical but realistic maximum performance of such tandem cells by means of full numerical simulations considering perfect layers and interfaces. The consequences of using a thin epi-Si bottom cell instead of a thick silicon substrate are investigated. In case no light trapping scheme is considered, a minimum epi-layer thickness of 20 μm is mandatory for the tandem to exhibit higher conversion efficiencies than a single GaAs solar cell. The epi-Si can yet be advantageously replaced by an epitaxial silicon-germanium alloy to increase the bottom cell optical absorption and thus decrease the minimum required thickness by a factor of ∼4 (∼5 μm). Finally, simulations show that over 33% efficiency can be obtained for AlxGa1-xAs/epi-Si0.63Ge0.27, which confirms that this is a promising new concept.
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- 2015
- Full Text
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19. Tin dioxide nanoparticles as catalyst precursors for plasma-assisted vapor–liquid–solid growth of silicon nanowires with well-controlled density
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Martin Foldyna, Wanghua Chen, Hamza Mohsin, Thierry Gacoin, Isabelle Maurin, Weixi Wang, Jean-Paul Kleider, José Alvarez, Jean-Luc Maurice, Pere Roca i Cabarrocas, Letian Dai, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Laboratoire Génie électrique et électronique de Paris (GeePs), Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de la Matière Condensée (LPMC), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de la matière condensée (LPMC), and École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)
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Materials science ,Nanoparticle ,chemistry.chemical_element ,Bioengineering ,02 engineering and technology ,Substrate (electronics) ,Chemical vapor deposition ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,chemistry.chemical_compound ,Deposition (phase transition) ,General Materials Science ,Electrical and Electronic Engineering ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,ComputingMilieux_MISCELLANEOUS ,[PHYS]Physics [physics] ,Tin dioxide ,Mechanical Engineering ,General Chemistry ,[CHIM.MATE]Chemical Sciences/Material chemistry ,equipment and supplies ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Chemical engineering ,Mechanics of Materials ,Particle ,0210 nano-technology ,Tin ,Layer (electronics) - Abstract
The fabrication of arrays of silicon nanowires (Si NWs) with well-defined surface coverage using the vapor-liquid-solid process requires a good control of the density and size distribution for the metal catalyst. We report on a cost-effective bottom-up approach to produce Si NWs by a low-temperature deposition technology using plasma-enhanced chemical vapor deposition and tin dioxide (SnO2) nanoparticles as the source of tin catalyst. This strategy offers a straightforward method to select specific particle sizes by conventional colloidal techniques, and to tune the surface coverage using a polyelectrolyte layer to efficiently immobilize the particles on the substrate by electrostatic grafting. After a further step of reduction into tin metal droplets using hydrogen plasma treatment, the catalyst particles are used for the growth of Si NWs. This approach allows the prodcution of controlled Si NWs arrays which can be used as a template for radial junction thin film solar cells.
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- 2018
20. Optical Study and Experimental Realization of Nanostructured Back Reflectors with Reduced Parasitic Losses for Silicon Thin Film Solar Cells
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Pavel Bulkin, Erik Johnson, Pere I Roca Cabarrocas, Zeyu Li, Martin Foldyna, E. Rusli, Chenjin Lu, Ari Bimo Prakoso, Rasha Khoury, Junkang Wang, Wanghua Chen, Nanayang Technological University (NTU), Nanayang Technological University, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), School of Electrical and Electronic Engineering, and Nanoelectronics Center of Excellence
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Amorphous silicon ,Materials science ,animal structures ,Silicon ,genetic structures ,General Chemical Engineering ,chemistry.chemical_element ,02 engineering and technology ,Chemical vapor deposition ,7. Clean energy ,01 natural sciences ,Article ,lcsh:Chemistry ,chemistry.chemical_compound ,Photovoltaics ,polystyrene sphere assisted lithography ,0103 physical sciences ,nanostructured back reflectors ,General Materials Science ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,Lithography ,Light Trapping ,ComputingMilieux_MISCELLANEOUS ,010302 applied physics ,[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] ,Plasma etching ,silicon thin film ,business.industry ,Energy conversion efficiency ,technology, industry, and agriculture ,Silicon Thin Film ,021001 nanoscience & nanotechnology ,equipment and supplies ,photovoltaics ,chemistry ,lcsh:QD1-999 ,Engineering::Electrical and electronic engineering [DRNTU] ,Optoelectronics ,light trapping ,0210 nano-technology ,business ,Layer (electronics) - Abstract
We study light trapping and parasitic losses in hydrogenated amorphous silicon thin film solar cells fabricated by plasma-enhanced chemical vapor deposition on nanostructured back reflectors. The back reflectors are patterned using polystyrene assisted lithography. By using O2 plasma etching of the polystyrene spheres, we managed to fabricate hexagonal nanostructured back reflectors. With the help of rigorous modeling, we study the parasitic losses in different back reflectors, non-active layers, and last but not least the light enhancement effect in the silicon absorber layer. Moreover, simulation results have been checked against experimental data. We have demonstrated hexagonal nanostructured amorphous silicon thin film solar cells with a power conversion efficiency of 7.7% and around 34.7% enhancement of the short-circuit current density, compared with planar amorphous silicon thin film solar cells. Published version
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- 2018
21. Molecular Beam Epitaxy of Germanium in the Atomic-Resolution Transmission Electron Microscope
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Laurent Travers, Federico Panciera, Eric Ngo, Martin Foldyna, Jean-Christophe Harmand, Ileana Florea, Weixi Wang, Pere Roca i Cabarrocas, Jean-Luc Maurice, Maurice, Jean-Luc, Equipements d'excellence - Microscopie electronique en transmission sur le plateau Palaiseau Orsay Saclay - - TEMPOS2010 - ANR-10-EQPX-0050 - EQPX - VALID, Croissance vapeur-liquide-solide de nanofils de silicium de phase hexagonale diamant - - HexaNW2017 - ANR-17-CE09-0011 - AAPG2017 - VALID, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centre de Nanosciences et de Nanotechnologies (C2N), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), ANR-10-EQPX-0050,TEMPOS,Microscopie electronique en transmission sur le plateau Palaiseau Orsay Saclay(2010), ANR-17-CE09-0011,HexaNW,Croissance vapeur-liquide-solide de nanofils de silicium de phase hexagonale diamant(2017), Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Centre de Nanosciences et de Nanotechnologies [Marcoussis] (C2N), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Réseau nanophotonique et optique, and Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)
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010302 applied physics ,Materials science ,business.industry ,chemistry.chemical_element ,Germanium ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,[PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,chemistry ,Atomic resolution ,Transmission electron microscopy ,0103 physical sciences ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Optoelectronics ,0210 nano-technology ,business ,Instrumentation ,ComputingMilieux_MISCELLANEOUS ,Molecular beam epitaxy - Abstract
International audience
- Published
- 2019
22. Natural occurrence of the diamond hexagonal structure in silicon nanowires grown by a plasma-assisted vapour-liquid-solid method
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Lianbo Yu, Erik Johnson, Jean-Luc Maurice, Wanghua Chen, Ileana Florea, J. Tang, P. Roca i Cabarrocas, Frédéric Fossard, Martin Foldyna, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'étude des microstructures [Châtillon] (LEM - ONERA - CNRS), Centre National de la Recherche Scientifique (CNRS)-ONERA, School of Electronics Engineering and Computer Science [Beijing] (EECS), and Peking University [Beijing]
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Materials science ,Nanowire ,chemistry.chemical_element ,02 engineering and technology ,Crystal structure ,engineering.material ,01 natural sciences ,NANOFILS ,Metastability ,Phase (matter) ,0103 physical sciences ,General Materials Science ,010306 general physics ,PLASMA ,Zone axis ,Diamond ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Crystallography ,Chemical engineering ,chemistry ,Transmission electron microscopy ,SILICIUM ,engineering ,0210 nano-technology ,Tin - Abstract
International audience; Silicon nanowires have been grown by a plasma-assisted vapour–liquid–solid method using tin as the catalyst. Transmission electron microscopy in the [1-210] zone axis shows that the diamond hexagonal (P63/mmc) crystal structure is present in several nanowires. This is the first unambiguous proof of the natural occurrence of this metastable phase to our knowledge.
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- 2017
23. Tuning the properties of F:SnO 2 (FTO) nanocomposites with S:TiO 2 nanoparticles – promising hazy transparent electrodes for photovoltaics applications
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Jean-Luc Deschanvres, Hervé Roussel, Carmen Jiménez, Lukas Schmidt-Mende, Shan-Ting Zhang, David Muñoz-Rojas, Etienne Pernot, Daniel Bellet, Vincent Consonni, Martin Foldyna, Laetitia Rapenne, Laboratoire des matériaux et du génie physique (LMGP ), Institut National Polytechnique de Grenoble (INPG)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire réactivité et chimie des solides - UMR CNRS 7314 (LRCS), and Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
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010302 applied physics ,Materials science ,Nanocomposite ,business.industry ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Epitaxy ,01 natural sciences ,7. Clean energy ,Photovoltaics ,0103 physical sciences ,Electrode ,Materials Chemistry ,nanocomposites ,nanoparticles, photovoltaics ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,ddc:530 ,Texture (crystalline) ,0210 nano-technology ,business ,Sheet resistance ,ComputingMilieux_MISCELLANEOUS ,Transparent conducting film - Abstract
The appropriate choice of nanoparticles is proved to be essential in tuning the properties of F:SnO2 (FTO) nanocomposites. With the use of more conductive sulphur-doped TiO2 (S:TiO2) nanoparticles, the sheet resistance of S:TiO2–FTO nanocomposites is successfully reduced down to 38% as compared to the standard flat FTO (11.7 Ω sq-1), while the haze factor of the S:TiO2–FTO nanocomposites can be varied from almost zero (reference flat FTO) up to 60%; moreover the majority of 〈110〉 oriented S:TiO2 nanoparticles leads to a strong (110) texture in the resulting S:TiO2–FTO nanocomposites by local epitaxy. Careful morphology analyses and angle-resolved measurements reveal that the haze factor is proportional to the total surface coverage of the S:TiO2 nanoparticle agglomerates, while the feature size of the agglomerates determines the angular distribution of the scattered light – this is confirmed by an angle-resolved Mueller matrix polarimeter which allows obtaining the optical microscopic and angleresolved images of the exact same textured region. Our work establishes the guidelines to fabricate FTO and other transparent conductive oxide (TCO) nanocomposites as promising electrodes in solar cells with tunable structural, electrical, and optical properties. published
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- 2017
24. TEM characterisation of diamond-hexagonal silicon nanowires
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Jean-Luc Maurice, Jian Tang, Ileana Florea, Frédéric Fossard, Pere Roca i Cabarrocas, Erik V. Johnson, and Martin Foldyna
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- 2016
25. Detailed analysis of III-V/epi-SiGe tandem solar cell performance including light trapping schemes
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Raphaël Lachaume, Martin Foldyna, José Alvarez, Jean Decobert, Gwenaëlle Hamon, Jean-Paul Kleider, Romain Cariou, P. Roca i Cabarrocas, Laboratoire Génie électrique et électronique de Paris (GeePs), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Total New Energies, Alcatel-Thalès III-V lab (III-V Lab), THALES [France]-ALCATEL, Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Sud - Paris 11 (UP11), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), and THALES-ALCATEL
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Light trapping ,Materials science ,Silicon ,Opto-electrical modeling ,chemistry.chemical_element ,Reflector (antenna) ,02 engineering and technology ,Grating ,01 natural sciences ,7. Clean energy ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Optics ,Epitaxial silicon germanium ,0103 physical sciences ,Texture (crystalline) ,Thin film ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,Absorption (electromagnetic radiation) ,010302 applied physics ,TCAD ,Tandem ,Renewable Energy, Sustainability and the Environment ,business.industry ,Open-circuit voltage ,Tandem solar cells ,III-V on silicon ,021001 nanoscience & nanotechnology ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,[SPI.TRON]Engineering Sciences [physics]/Electronics ,chemistry ,Optoelectronics ,0210 nano-technology ,business ,RCWA - Abstract
International audience; Recent developments have unlocked the main issues arising from the combination of III-V and silicon and have opened a new way to fabricate tandem solar cells. In this study we provide a detailed analysis of III-V/epi-SiGe tandem devices performance using opto-electrical models and parameters acquired from previous experimental realizations of single junction devices. At first, we present the validation of our top and bottom cells models by comparison with previously published solar cells. The analysis of the current matching and the impact of the Al content in AlGaAs absorber on the open circuit voltage is performed on a very wide range of thickness and Al content. The optimal configurations for tandems with thin film absorbers are found with an empirical expression. This expression relates the required bottom absorber thickness to the Al content for current matching in a flat tandem device. Low-temperature epitaxial SiGe growth on III-V materials is an inverted growth technique, meaning that the last material grown is the Si(Ge) bottom cell. We can thus easily texture the back of the bottom cell for higher photon absorption. The proposed nanostructurization of the back reflector shows that, to reach the same efficiency, only half of the thickness is required if a 2D grating is combined with a silver reflector. The detailed influence of the bulk and interface electrical quality in the epi-SiGe bottom cell is also assessed. Finally, the prediction of the tandem device performance according to different realistic scenarios is presented.
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- 2016
26. Plasma-Assisted Growth of Silicon Nanowires by Sn Catalyst: Step-by-Step Observation
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Jean-Luc Maurice, Soumyadeep Misra, Pere Roca i Cabarrocas, J. Tang, Erik Johnson, Wanghua Chen, Martin Foldyna, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), and Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)
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Sn ,Materials science ,PECVD ,Nanowire ,Shell (structure) ,Nanochemistry ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,01 natural sciences ,VLS ,Monocrystalline silicon ,Crystallinity ,Materials Science(all) ,Silicon nanowires ,Plasma-enhanced chemical vapor deposition ,0103 physical sciences ,General Materials Science ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,ComputingMilieux_MISCELLANEOUS ,010302 applied physics ,Nano Express ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Amorphous solid ,Chemical engineering ,chemistry ,Growth process ,0210 nano-technology ,Tin - Abstract
A comprehensive study of the silicon nanowire growth process has been carried out. Silicon nanowires were grown by plasma-assisted-vapor-solid method using tin as a catalyst. We have focused on the evolution of the silicon nanowire density, morphology, and crystallinity. For the first time, the initial growth stage, which determines the nanowire (NW) density and growth direction, has been observed step by step. We provide direct evidence of the merging of Sn catalyst droplets and the formation of Si nanowires during the first 10 s of growth. We found that the density of Sn droplets decreases from ~9000 Sn droplets/μm2 to 2000 droplets/μm2 after just 10 s of growth. Moreover, the long and straight nanowire density decreases from 170/μm2 after 2 min of growth to less than 10/μm2 after 90 min. This strong reduction in nanowire density is accompanied by an evolution of their morphology from cylindrical to conical, then to bend conical, and finally, to a bend inverted conical shape. Moreover, the changes in the crystalline structure of nanowires are from (i) monocrystalline to (ii) monocrystalline core/defective crystalline shell and then to (iii) monocrystalline core/defective crystalline shell/amorphous shell. The evolutions of NW properties have been explained in detail.
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- 2016
27. Ultrathin Epitaxial Silicon Solar Cells with Inverted Nanopyramid Arrays for Efficient Light Trapping
- Author
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Christophe Dupuis, Romain Cariou, Loïc Lalouat, Wanghua Chen, Pere Roca i Cabarrocas, Emmanuel Drouard, Christian Seassal, Stéphane Collin, Anne Gaucher, Andrea Cattoni, Martin Foldyna, Institut Lavoisier de Versailles ( ILV ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de photonique et de nanostructures ( LPN ), Centre National de la Recherche Scientifique ( CNRS ), Faculté Polytechnique de Mons, Laboratoire de physique des interfaces et des couches minces [Palaiseau] ( LPICM ), École polytechnique ( X ) -Centre National de la Recherche Scientifique ( CNRS ), Alcatel-Thalès III-V lab ( III-V Lab ), THALES-ALCATEL, Laboratoire Interdisciplinaire Carnot de Bourgogne ( LICB ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), INL - Nanophotonique ( INL - Photonique ), Institut des Nanotechnologies de Lyon ( INL ), École Centrale de Lyon ( ECL ), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon ( CPE ) -Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ) -École Centrale de Lyon ( ECL ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), Université de Lyon, LPN-CNRS, Route de Nozay, 91460 Marcoussis, France, Laboratoire d'Electronique et des Technologies de l'Information ( CEA-LETI ), Université Grenoble Alpes [Saint Martin d'Hères]-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Department of Geology and Applied Geology, University of Mons [Belgium] ( UMONS ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS ) -Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -École supérieure de Chimie Physique Electronique de Lyon ( CPE ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-École Centrale de Lyon ( ECL ), Laboratoire Traitement du Signal et de l'Image ( LTSI ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Grenoble Alpes [Saint Martin d'Hères], Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Faculté polytechnique de Mons, Université de Mons (UMons), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Alcatel-Thalès III-V lab (III-V Lab), Laboratoire Interdisciplinaire Carnot de Bourgogne (LICB), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), INL - Nanophotonique (INL - Photonique), Institut des Nanotechnologies de Lyon (INL), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)
- Subjects
Fabrication ,Materials science ,crystalline silicon ,Bioengineering ,02 engineering and technology ,Epitaxy ,7. Clean energy ,01 natural sciences ,Nanoimprint lithography ,law.invention ,Monocrystalline silicon ,law ,Plasma-enhanced chemical vapor deposition ,0103 physical sciences ,[ SPI ] Engineering Sciences [physics] ,nanoimprint lithography ,General Materials Science ,Crystalline silicon ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,ComputingMilieux_MISCELLANEOUS ,010302 applied physics ,business.industry ,Mechanical Engineering ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,low-temperature epitaxy ,Anodic bonding ,solar cells ,Optoelectronics ,light trapping ,Quantum efficiency ,[ SPI.NANO ] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,[ SPI.OPTI ] Engineering Sciences [physics]/Optics / Photonic ,0210 nano-technology ,business ,[ PHYS.COND ] Physics [physics]/Condensed Matter [cond-mat] - Abstract
International audience; Ultrathin c-Si solar cells have the potential to drastically reduce costs by saving raw material while maintaining good efficiencies thanks to the excellent quality of monocrystalline silicon. However, efficient light trapping strategies must be implemented to achieve high short-circuit currents. We report on the fabrication of both planar and patterned ultrathin c-Si solar cells on glass using low temperature (T < 275 °C), low-cost, and scalable techniques. Epitaxial c-Si layers are grown by PECVD at 160 °C and transferred on a glass substrate by anodic bonding and mechanical cleavage. A silver back mirror is combined with a front texturation based on an inverted nanopyramid array fabricated by nanoimprint lithography and wet etching. We demonstrate a short-circuit current density of 25.3 mA/cm2 for an equivalent thickness of only 2.75 μm. External quantum efficiency (EQE) measurements are in very good agreement with FDTD simulations. We infer an optical path enhancement of 10 in the long wavelength range. A simple propagation model reveals that the low photon escape probability of 25% is the key factor in the light trapping mechanism. The main limitations of our current technology and the potential efficiencies achievable with contact optimization are discussed.
- Published
- 2016
28. Cross-sectional investigations on epitaxial silicon solar cells by Kelvin and Conducting Probe Atomic Force Microscopy: Effect of illumination
- Author
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Romain Cariou, Pascal Chrétien, Patricia Prod'Homme, Jean-Paul Kleider, Martin Foldyna, Paul Narchi, José Alvarez, Gennaro Picardi, Pere Roca i Cabarrocas, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Total M&S [Paris La Defense], TOTAL FINA ELF, Laboratoire Génie électrique et électronique de Paris (GeePs), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Alcatel-Thalès III-V lab (III-V Lab), THALES-ALCATEL, Total New Energies, Institut Photovoltaïque d’Ile-de-France (ITE) (IPVF), THALES [France]-ALCATEL, and KLEIDER, Jean-Paul
- Subjects
Materials science ,[SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic ,[SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,Surface photovoltage ,Analytical chemistry ,02 engineering and technology ,[SPI.MAT] Engineering Sciences [physics]/Materials ,Epitaxy ,Kelvin probe force microscopy ,7. Clean energy ,01 natural sciences ,law.invention ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Materials Science(all) ,law ,0103 physical sciences ,Solar cell ,Microscopy ,Photocurrent ,General Materials Science ,Epitaxial silicon ,Crystalline silicon ,Conducting probe atomic force microscopy ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,ComputingMilieux_MISCELLANEOUS ,010302 applied physics ,Kelvin probe force microscope ,Nano Express ,business.industry ,[SPI.NRJ]Engineering Sciences [physics]/Electric power ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,[PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Optoelectronics ,Photovoltage ,0210 nano-technology ,business ,[SPI.NRJ] Engineering Sciences [physics]/Electric power ,Visible spectrum - Abstract
International audience; Both surface photovoltage and photocurrent enable to assess the effect of visible light illumination on the electrical behavior of a solar cell. We report on photovoltage and photocurrent measurements with nanometer scale resolution performed on the cross section of an epitaxial crystalline silicon solar cell, using respectively Kelvin probe force microscopy and conducting probe atomic force microscopy. Even though two different setups are used, the scans were performed on locations within 100-μm distance in order to compare data from the same area and provide a consistent interpretation. In both measurements, modifications under illumination are observed in accordance with the theory of PIN junctions. Moreover, an unintentional doping during the deposition of the epitaxial silicon intrinsic layer in the solar cell is suggested from the comparison between photovoltage and photocurrent measurements.
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- 2015
29. Sum decomposition of Mueller-matrix images and spectra of beetle cuticles
- Author
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Clément Fallet, A. De Martino, Roger Magnusson, Kenneth Järrendahl, Razvigor Ossikovski, Hans Arwin, Enric Garcia-Caurel, Martin Foldyna, Laboratory of Applied Optics, Linköping University (LIU), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), and École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)
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medicine.medical_specialty ,Physics::Optics ,02 engineering and technology ,01 natural sciences ,Spectral line ,law.invention ,010309 optics ,Optics ,law ,0103 physical sciences ,medicine ,Fysik ,Mueller calculus ,Eigenvalues and eigenvectors ,Physics ,[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] ,Spatial filter ,business.industry ,Polarizer ,Covariance ,021001 nanoscience & nanotechnology ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,Spectral imaging ,Physical Sciences ,0210 nano-technology ,business - Abstract
International audience; Spectral Mueller matrices measured at multiple angles of incidence as well as Mueller matrix images are recorded on the exoskeletons (cuticles) of the scarab beetles Cetonia aurata and Chrysina argenteola. Cetonia aurata is green whereas Chrysina argenteola is gold-colored. When illuminated with natural (unpolarized) light, both species reflect left-handed and near-circularly polarized light originating from helicoidal structures in their cuticles. These structures are referred to as circular Bragg reflectors. For both species the Mueller matrices are found to be nondiagonal depolarizers. The matrices are Cloude decomposed to a sum of non-depolarizing matrices and it is found that the cuticle optical response, in a first approximation can be described as a sum of Mueller matrices from an ideal mirror and an ideal circular polarizer with relative weights determined by the eigenvalues of the covariance matrices of the measured Mueller matrices. The spectral and image decompositions are consistent with each other. A regression-based decomposition of the spectral and image Mueller matrices is also presented whereby the basic optical components are assumed to be a mirror and a circular polarizer as suggested by the Cloude decomposition. The advantage with a regression decomposition compared to a Cloude decomposition is its better stability as the matrices in the decomposition are determined a priori. The origin of the depolarizing features are discussed but from present data it is not possible to conclude whether the two major components, the mirror and the circular polarizer are laterally separated in domains in the cuticle or if the depolarization originates from the intrinsic properties of the helicoidal structure.-matrix characterization of bee-tle cuticle: polarized and unpolarized reflections from representative architectures," Appl. Opt. 49, 4558–4567 (2010).-induced polarization effects in the cuticle of scarab beetles: 100 years after Michelson," Phil. Mag. 92, 1583–1599 (2012). 4. H. Arwin, T. Berlind, B. Johs, and K. Järrendahl, "Cuticle structure of the scarab beetle Cetonia aurata analyzed by regression analysis of Mueller-matrix ellipsometric data," Opt. Express 21, 22645–22656 (2013). 5. matrices: how to decompose them?," Phys. Status Solidi A 205, 720–727 (2008). 6. S. R. Cloude, "Group theory and polarization algebra," Optik (Stuttgart) 75, 26–36 (1986). 7. S. R. Cloude and E. Pottier, "A review of target decomposition theorems in radar polarimetry," IEEE Trans.
- Published
- 2015
30. Plasma nanotexturing of silicon surfaces for photovoltaics applications: influence of initial surface finish on the evolution of topographical and optical properties
- Author
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Guillaume Fischer, Etienne Drahi, Thomas A. Germer, Erik Johnson, Martin Foldyna, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut Photovoltaïque d’Ile-de-France (ITE) (IPVF), Total New Energies R&D Concentrated Solar Technologies, Total New Energies, Computer Security Division (NIST), National Institute of Standards and Technology [Gaithersburg] (NIST), and Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)
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Materials science ,Silicon ,chemistry.chemical_element ,02 engineering and technology ,Surface finish ,01 natural sciences ,7. Clean energy ,Article ,chemistry.chemical_compound ,Optics ,Etching (microfabrication) ,0103 physical sciences ,Surface roughness ,Crystalline silicon ,Nanotextured Surfaces ,ComputingMilieux_MISCELLANEOUS ,010302 applied physics ,business.industry ,Black silicon ,021001 nanoscience & nanotechnology ,Atomic and Molecular Physics, and Optics ,chemistry ,Physical vapor deposition ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,0210 nano-technology ,business - Abstract
Using a plasma to generate a surface texture with feature sizes on the order of tens to hundreds of nanometers (“nanotexturing”) is a promising technique being considered to improve efficiency in thin, high-efficiency crystalline silicon solar cells. This study investigates the evolution of the optical properties of silicon samples with various initial surface finishes (from mirror polish to various states of micron-scale roughness) during a plasma nanotexturing process. It is shown that during said process, the appearance and growth of nanocone-like structures are essentially independent of the initial surface finish, as quantified by the auto-correlation function of the surface morphology. During the first stage of the process (2 min to 15 min etching), the reflectance and light-trapping abilities of the nanotextured surfaces are strongly influenced by the initial surface roughness; however, the differences tend to diminish as the nanostructures become larger. For the longest etching times (15 min or more), the effective reflectance is less than 5 % and a strong anisotropic scattering behavior is also observed for all samples, leading to very elevated levels of light-trapping.
- Published
- 2017
31. Understanding Light Harvesting in Radial Junction Amorphous Silicon Thin Film Solar Cells
- Author
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Martin Foldyna, Erik Johnson, Soumyadeep Misra, Pere Roca i Cabarrocas, Yi Shi, Jun Xu, Linwei Yu, Shengyi Qian, Junzhuan Wang, College of Information and Electrical Engineering [Beijing] (CIEE), China Agricultural University (CAU), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Department of Aerospace Engineering, Old Dominion University [Norfolk] (ODU), School of Mechanical Engineering, Yeungnam University, University of Illinois at Urbana Champaign (UIUC), University of Illinois at Urbana-Champaign [Urbana], University of Illinois System-University of Illinois System, Shanghai Institutes for Biological Sciences, and Chinese Academy of Sciences [Beijing] (CAS)-Shanghai Jiao Tong University School of Medicine
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Amorphous silicon ,Silicon ,Theory of solar cells ,Multidisciplinary ,Materials science ,business.industry ,Membranes, Artificial ,Equipment Design ,Solar energy ,7. Clean energy ,Article ,Polymer solar cell ,chemistry.chemical_compound ,Electric Power Supplies ,chemistry ,Photovoltaics ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Solar Energy ,Sunlight ,Optoelectronics ,Plasmonic solar cell ,Thin film ,business ,Absorption (electromagnetic radiation) ,ComputingMilieux_MISCELLANEOUS - Abstract
The radial junction (RJ) architecture has proven beneficial for the design of a new generation of high performance thin film photovoltaics. We herein carry out a comprehensive modeling of the light in-coupling, propagation and absorption profile within RJ thin film cells based on an accurate set of material properties extracted from spectroscopic ellipsometry measurements. This has enabled us to understand and evaluate the impact of varying several key parameters on the light harvesting in radially formed thin film solar cells. We found that the resonance mode absorption and antenna-like light in-coupling behavior in the RJ cell cavity can lead to a unique absorption distribution in the absorber that is very different from the situation expected in a planar thin film cell and that has to be taken into account in the design of high performance RJ thin film solar cells. When compared to the experimental EQE response of real RJ solar cells, this modeling also provides an insightful and powerful tool to resolve the wavelength-dependent contributions arising from individual RJ units and/or from strong light trapping due to the presence of the RJ cell array.
- Published
- 2014
32. Modeling of magneto-optical properties of lamellar nanogratings
- Author
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Jaromír Pištora, Martin Foldyna, Dalibor Ciprian, and Kamil Postava
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Permittivity ,Chemistry ,business.industry ,Mechanical Engineering ,Metals and Alloys ,Physics::Optics ,Grating ,Computer Science::Digital Libraries ,symbols.namesake ,Transverse plane ,Optics ,Fourier transform ,Factorization ,Mechanics of Materials ,Materials Chemistry ,symbols ,Lamellar structure ,Tensor ,business ,S-matrix - Abstract
Optical and magneto-optical (MO) properties of the MO nanometer-size gratings (nanogratings) are modeled using improved rigorous couple wave analysis (RCWA). The improvements include S-matrix propagation algorithm and Fourier factorization rules and lead to necessary numerical precision for the modeled quantities. The rigorous model is compared with effective medium approximation (EMA), used for simple description of the grating parameters, and the areas of differences are discussed. Dependence of optical and MO elements of permittivity tensor on the fill factor is presented together with comparison to the EMA. Basic polar, longitudinal, and transverse MO configuration are studied.
- Published
- 2007
33. Mueller matrix ellipsometry of artificial non-periodic line edge roughness in presence of finite numerical aperture
- Author
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Brent C. Bergner, Thomas A. Germer, Martin Foldyna, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), and École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
periodic grating ,Materials science ,Mean squared error ,Silicon ,chemistry.chemical_element ,Physics::Optics ,02 engineering and technology ,Grating ,Line edge roughness ,01 natural sciences ,010309 optics ,Optics ,Ellipsometry ,line edge roughness ,0103 physical sciences ,[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] ,business.industry ,Mueller matrix ellipsometry ,021001 nanoscience & nanotechnology ,Numerical aperture ,Azimuth ,chemistry ,Line (geometry) ,0210 nano-technology ,business ,Finite numerical aperture - Abstract
International audience; We used azimuthally-resolved spectroscopic Mueller matrix ellipsometry to study a periodic silicon line structure with and without artificially-generated line edge roughness (LER). The unperturbed, reference grating profile was determined from multiple azimuthal configurations using a generalized ellipsometer, focusing the incident beam into a 60 μm spot. We used rigorous numerical modeling, taking into account the finite numerical aperture, introducing significant depolarization effects, and determining the profile shape using a four trapezoid model for the line profile. Data obtained from the artificially perturbed grating were then fit using the same model, and the resulting root-mean-square error (RMSE) values for both targets were compared. The comparison shows an increase in RMSE values for the perturbed grating that can be attributed to the effects of LER.
- Published
- 2011
34. Real-time in situ Mueller matrix ellipsometry of GaSb nanopillars: observation of anisotropic local alignment
- Author
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I. S. Nerbø, Elin Sondergard, Sébastien Roy, Martin Foldyna, Morten Kildemo, Physics Department, Norwegian University of Science and Technology, Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU)-Norwegian University of Science and Technology (NTNU), Surface du Verre et Interfaces (SVI), Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Physics Department, Nowegian University of Science and Technology, and Physics Department
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Antimony ,spectroscopy ,Materials science ,reflectance ,Scanning electron microscope ,growth ,Gallium ,02 engineering and technology ,Dielectric ,Substrate (electronics) ,01 natural sciences ,010309 optics ,Optics ,angle ,Ellipsometry ,0103 physical sciences ,Nanotechnology ,arrays ,Thin film ,Anisotropy ,ComputingMilieux_MISCELLANEOUS ,Nanopillar ,business.industry ,Orthogonal polarization spectral imaging ,Models, Theoretical ,021001 nanoscience & nanotechnology ,Atomic and Molecular Physics, and Optics ,Nanostructures ,optical-properties ,thin-films ,Microscopy, Electron, Scanning ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Microscopy, Polarization ,0210 nano-technology ,business - Abstract
The formation of GaSb nanopillars by low energy ion sputtering is studied in real-time by spectroscopic Mueller matrix ellipsometry, from the initial formation in the smooth substrate until nanopillars with a height of 200 – 300 nm are formed. As the nanopillar height increased above 100 nm, coupling between orthogonal polarization modes was observed. Ex situ angle resolved Mueller polarimetry measurements revealed a 180° azimuth rotation symmetry in the off-diagonal Mueller elements, which can be explained by a biaxial material with different dielectric functions εx and εy in a plane parallel to the substrate. This polarization coupling can be caused by a tendency for local direction dependent alignment of the pillars, and such a tendency is confirmed by scanning electron microscopy. Such observations have not been made for GaSb nanopillars shorter than 100 nm, which have optical properties that can be modeled as a uniaxial effective medium. Open Access
- Published
- 2011
35. Profile characterization of diffraction gratings using angle-resolved polarimetric measurements
- Author
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Christophe Licitra, Martin Foldyna, S. Ben Hatit, J. Foucher, and A. De Martino
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Engineering ,business.industry ,Physics ,QC1-999 ,Polarimetry ,Characterization (materials science) ,Azimuth ,Optics ,Calibration ,Mueller calculus ,Sensitivity (control systems) ,business ,Anisotropy ,Diffraction grating - Abstract
Development of the characterization tools and techniques used by semi-conductor industry directs not only towards increasing of the instrumental precision, to push limits of the optical characterization methods to the smallest lines, but also towards a decreased dependency of the used tools on the tool-to-tool calibration procedures. The challenge approached in this work is to use multiple independent optical configurations to determine overall accuracy of the results with minimal or no assistance of the other non-optical methods. The approach presented here is based on a well-known change of sensitivity of the optical model parameters at the different azimuthal measurement configurations. The full potential of this method can only be unlocked using complete Mueller matrix measurements providing complete information on the anisotropic nature of the gratings. The measurements at multiple azimuth configurations, used in this work, illustrate the potential of the method on the experimental data provided by the angle-resolved and spectrally resolved Mueller matrix polarimetric tools. The results are consistent with the single-line AFM measurements used as an independent reference.
- Published
- 2010
36. Retrieval of a non-depolarizing component of experimentally determined depolarizing Mueller matrices
- Author
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Razvigor Ossikovski, Martin Foldyna, Enric Garcia-Caurel, José J. Gil, and A. De Martino
- Subjects
Optics and Photonics ,Light ,Physics::Optics ,Boundary (topology) ,Superposition principle ,Matrix (mathematics) ,Optics ,polycyclic compounds ,Image Processing, Computer-Assisted ,Mueller calculus ,Algebraic number ,Diffraction grating ,Physics ,Models, Statistical ,Quantitative Biology::Neurons and Cognition ,business.industry ,Astrophysics::Instrumentation and Methods for Astrophysics ,biochemical phenomena, metabolism, and nutrition ,Mathematics::Spectral Theory ,equipment and supplies ,Sample (graphics) ,Atomic and Molecular Physics, and Optics ,bacteria ,Physics::Accelerator Physics ,Microscopy, Polarization ,business ,Beam (structure) ,Algorithms - Abstract
The measurement of the Mueller matrix when the probing beam is placed on the boundary between two (or more) regions of the sample with different optical properties may lead to a depolarization in the Mueller matrix. The depolarization is due to the incoherent superposition of the optical responses of different sample regions in the probe beam. Despite of the depolarization, the measured Mueller matrix has information enough to subtract a Mueller matrix corresponding to one of the regions of sample provided that this subtracted matrix is non-depolarizing. For clarity, we will call these non-depolarizing Mueller matrices of one individual region of the sample simply as the non-depolarizing components. In the framework of the theory of Mueller matrix algebra, we have implemented a procedure allowing the retrieval of a non-depolarizing component from a depolarizing Mueller matrix constituted by the sum of several non-depolarizing components. In order to apply the procedure, the Mueller matrices of the rest of the non-depolarizing components have to be known. Here we present a numerical and algebraic approaches to implement the subtraction method. To illustrate our method as well as the performance of the two approaches, we present two practical examples. In both cases we have measured depolarizing Mueller matrices by positioning an illumination beam on the boundary between two and three different regions of a sample, respectively. The goal was to retrieve the non-depolarizing Mueller matrix of one of those regions from the measured depolarizing Mueller matrix. In order to evaluate the performance of the method we compared the subtracted matrix with the Mueller matrix of the selected region measured separately.
- Published
- 2009
37. Effective medium approximation of anisotropic lamellar nanogratings based on Fourier factorization
- Author
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Koki Watanabe, Bernard Drevillon, Kamil Postava, Martin Foldyna, Razvigor Ossikovski, Antonello De Martino, Jaromír Pištora, and Dalibor Ciprian
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Diffraction ,periodic nanostructures ,Materials science ,business.industry ,Physics::Optics ,diffraction gratings ,materials and process characterization ,Atomic and Molecular Physics, and Optics ,ellipsometry and polarimetry ,symbols.namesake ,gratings ,Optics ,Fourier transform ,Factorization ,Harmonics ,anisotropic optical materials ,symbols ,Lamellar structure ,business ,Anisotropy ,Rigorous coupled-wave analysis ,Refractive index - Abstract
Anisotropic lamellar sub-wavelength gratings (nanogratings) are described by Effective Medium Approximation (EMA). Analytical formulas for effective medium optical parameters of nanogratings from arbitrary anisotropic materials are derived using approximation of zero-order diffraction mode. The method is based on Rigorous Coupled Wave Analysis (RCWA) combined with proper Fourier factorization method. Good agreement between EMA and the rigorous model is observed, where slight differences are explained by the influence of evanescent higher Fourier harmonics in the nanograting.
- Published
- 2009
38. Critical dimensions of biperiodic gratings determined by spectral ellipsometry and Mueller matrix polarimetry
- Author
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Martin Foldyna, A. De Martino, Enric Garcia-Caurel, Kamil Postava, F. Bertin, C. Licitra, Razvigor Ossikovski, Bernard Drevillon, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Departament of Physics, and Technical University of Ostrava [Ostrava] (VSB)
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Diffraction ,Polarimeters and ellipsometers ,Materials science ,Polarimetry ,02 engineering and technology ,01 natural sciences ,010309 optics ,Optics ,Ellipsometry ,0103 physical sciences ,Mueller calculus ,Instrumentation ,Gratings ,[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] ,business.industry ,Optical polarization ,Conical surface ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Azimuth ,Metrological applications ,0210 nano-technology ,business ,Critical dimension ,optical frequency synthesizers for precision spectroscopy - Abstract
International audience; We characterized two samples consisting of photoresist layers on silicon with square arrays of square holes by spectroscopic ellipsometry (SE) and Mueller matrix polarimetry (MMP). Hole lateral dimensions and depths were determined by fitting either SE data taken in conventional planar geometry or MMP data in general conical diffraction configurations. A method for objective determination of the optimal measurement conditions based on sensitivity and parameter correlations is presented.When applied to MMP, this approach showed that for one of the samples the optimal incidence angle was 45◦, much below the widely used 70 degrees value. The robustness of the dimensional characterisation based on MMP is demonstrated by the high stability of the results provided by separated fits of the data taken at different azimuthal angles.
- Published
- 2008
39. Effective spectral optical functions of lamellar nanogratings
- Author
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Enric Garcia-Caurel, Martin Foldyna, Kamil Postava, Razvigor Ossikovski, Antonello De Martino, and Garcia-Caurel, Enric
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[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics] ,Diffraction ,Materials science ,Birefringence ,business.industry ,Physics::Optics ,diffraction gratings ,Dielectric ,Linear dichroism ,Atomic and Molecular Physics, and Optics ,nanogratings ,Optics ,spectral optical functions ,anisotropic optical materials ,effective medium approximation ,Lamellar structure ,business ,Rigorous coupled-wave analysis ,Diffraction grating ,ComputingMilieux_MISCELLANEOUS ,Harmonic oscillator - Abstract
Spectral properties of lamellar sub-wavelength gratings (nanogratings) are described by effective medium approximation (EMA). Analytical spectral formulae for ordinary and extraordinary effective optical functions are derived for nanogratings consisting of material described by Sellmeier, damped harmonic oscillator, and Drude formulae. Spectral origin for birefringence of dielectric nanogratings and linear dichroism for absorbing ones is discussed for model cases and gratings consisting of real natural materials. Simple approximation by zero-order diffraction is compared with rigorous modeling based on Rigorous Coupled Wave Analysis (RCWA). Limits of applicability of effective medium approximation is discussed in the spectral domain. Web of Science 1 art. no. 06015
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- 2006
40. Characterization of inclined GaSb nanopillars by angle resolved Mueller polarimetry
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A. De Martino, Morten Kildemo, E. Søndergård, S. Le Roy, Martin Foldyna, and I. S. Nerbø
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Physics ,Carabus auratus ,biology ,business.industry ,Scattering ,QC1-999 ,biology.organism_classification ,Iridescence ,Optics ,Carabus auronitens ,business ,Absorption (electromagnetic radiation) ,Structural coloration ,Cuticle (hair) ,Nanopillar - Abstract
Color in living organisms is primarily generated by two mechanisms: selective absorption by pigments and structural coloration, or a combination of both. In this study, we investigated the coloration of cuticle from the wings (elytra) of the two ground beetle species Carabus auronitens and Carabus auratus. The greenish iridescent color of both species is created by a multilayer structure consisting of periodically alternating layers with different thicknesses and composition which is located in the 1-2 µm thick outermost layer of the cuticle (epicuticle). Illuminated with white light, reflectance spectra in both linear polarisation show an angle-dependent characteristic peak in the blue/green region of the spectrum. Furthermore, the reflected light is polarised linearly. Scattering experiments with laser illumination at 532 nm show diffuse scattering over a larger angular range. The polarisation dependence of the scattered light is consistent with the interpretation of small inhomogeneities as scattering centres in the elytra.
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- 2010
41. Individual Treatment with Stem Cell Rescue in Patients with Germ-Cell Tumors. Results of One Centrum
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Jitka Abrahámová, Martin Foldyna, Marcela Greplova, Markyta Bartova, Jana Nepomucka, Ludmila Pagacova, Zuzana Donátová, Jan Kalanin, and Drahomira Kordikova
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Oncology ,Chemotherapy ,medicine.medical_specialty ,Autologous Stem Cell Rescue ,Cyclophosphamide ,business.industry ,medicine.medical_treatment ,Immunology ,Cell Biology ,Hematology ,medicine.disease ,Biochemistry ,Gemcitabine ,Carboplatin ,Surgery ,Granulocyte colony-stimulating factor ,chemistry.chemical_compound ,chemistry ,Internal medicine ,Medicine ,Germ cell tumors ,business ,Etoposide ,medicine.drug - Abstract
Background: Treatment with high dose chemotherapy and autologous stem cell rescue in pacients with poor risk germ cell tumors is still controversial. Results of multicentric randomized EBMT study IT 94 presented at ASCO 2002 show benefit in 1-year EFS in high dose arm (52% versus 48%), 3-year EFS was the same in both arms (53%) in salvage treatment. Individual treatment with stem cell rescue as upfront treatment offers a survival benefit. Methods:Autologous stem cell rescue was provided in our center, from September 1997 to May 2006 to 52 patients. High dose chemotherapy was indicated to 32 patients in salvage setting after 2nd line of treatment (VeIP) and to 20 patients as upfront treatment after 1st line treatment (BEP). Median age was 29 years and tumor markers were elevated: HCG in 9 pts, AFP in 13 pts. Stem cell mobilization was performed after the 3rd cycle of VeIP or BEP in combination with G-CSF. The amount of CD34+ cell/kg b.w. was between 2,0 – 13.4×106. High - dose conditioning regimen CARBOPEC (carboplatin 1600 – 2 200 mg/m2, etoposide 1 800mg/m2, cyclophosphamide 6 400 mg/m2) was used. The treatment was well tolerated without transplant - related mortality. Results: WHO criteria non - hematological toxicity was predominantly grade 2 to 3. Engraftment was rapid, recovery of hematopoiesis in neutrofils over 1.0×109/l and platelets over 50×109/l was reached an average on days +10 and +13 respectively. Additional post-transplant treatment for persistence, progression or relaps had 20 patients (8pts had 2nd line treatment VEIP, 12pts had 3nd line treatment with paclitaxel+gemcitabine and 5 pts had retroperitoneal lymfadenectomy). The follow - up period ranges from 3 to 99 months, at present 38 (73 %) patients are alive, 14 (27 %) pts died. Median TTP of all pts is 10 months, median OS of all pts is 39 months. Median DFS of surviving pts is 38 months. Conclusion: high-dose chemotherapy with autologous stem cell rescue in patients with poor risk germ cell tumors is feasible and beneficial method of the individual treatment. High-dose chemotherapy as upfront treatment for poor prognosis germ cell tumors and as salvage treatment in good risk pts seems to be good possibility of the individual treatment.
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- 2006
42. Understanding Light Harvesting in Radial Junction Amorphous Silicon Thin Film Solar Cells.
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Linwei Yu, Soumyadeep Misra, Junzhuan Wang, Shengyi Qian, Martin Foldyna, Jun Xu, Yi Shi, Erik Johnson, and Pere Roca i Cabarrocas
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AMORPHOUS silicon ,THIN films ,SOLAR cells ,PHOTOVOLTAIC power generation ,ELLIPSOMETRY - Abstract
The radial junction (RJ) architecture has proven beneficial for the design of a new generation of high performance thin film photovoltaics. We herein carry out a comprehensive modeling of the light in-coupling, propagation and absorption profile within RJ thin film cells based on an accurate set of material properties extracted from spectroscopic ellipsometry measurements. This has enabled us to understand and evaluate the impact of varying several key parameters on the light harvesting in radially formed thin film solar cells. We found that the resonance mode absorption and antenna-like light in-coupling behavior in the RJ cell cavity can lead to a unique absorption distribution in the absorber that is very different from the situation expected in a planar thin film cell, and that has to be taken into account in the design of high performance RJ thin film solar cells. When compared to the experimental EQE response of real RJ solar cells, this modeling also provides an insightful and powerful tool to resolve the wavelength-dependent contributions arising from individual RJ units and/or from strong light trapping due to the presence of the RJ cell array. [ABSTRACT FROM AUTHOR]
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- 2014
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43. Tin reduction from fluorine doped tin oxide for silicon nanowire-based solar energy harvesting and storage
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Lukas, Halagacka, Zuzana, Gelnarova, Mutaz, Al-Ghzaiwat, Ileana, Florea, Jiri, Hornicek, Kamil, Postava, and Martin, Foldyna
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44. Colour optimization of phosphor-converted flexible nitride nanowire white light emitting diodes
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Nan Guan, François H. Julien, Junkang Wang, Martin Foldyna, Subrata Das, Maria Tchernycheva, Nuño Amador-Mendez, Christophe Durand, Akanksha Kapoor, Noelle Gogneau, Sudipta Som, Joël Eymery, Centre de Nanosciences et Nanotechnologies (C2N (UMR_9001)), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), National Institute for Interdisciplinary Science and Technology (CSIR), National Institute for Interdisciplinary Science and Technology [India], Nanophysique et Semiconducteurs (NPSC), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), National Taiwan University [Taiwan] (NTU), Nanostructures et Rayonnement Synchrotron (NRS ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
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Materials science ,business.industry ,Nanowire ,Phosphor ,Gallium nitride ,02 engineering and technology ,Nitride ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,White light ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Optoelectronics ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,ComputingMilieux_MISCELLANEOUS ,Diode - Abstract
We demonstrate flexible nanowire white light-emitting-diodes (LEDs) with an optimized colour quality. The devices consist of flexible InGaN/GaN nanowire LEDs acting as pumps, capped with removable phosphor-doped polydimethylsiloxane membranes. Five different phosphors with tens of microns in grain size emitting from green to orange are investigated using both violet-blue and a blue-green nanowire-based LED pumps. In addition, a flexible nanowire white LED with a warm white emission is demonstrated using two layers of different phosphors. Compared to the previous realizations of flexible nanowire white LEDs, these novel LEDs improve the colour rendering index from 54 to 86 and show a colour tuneable from a bluish cool white colour to natural white and finally to warm white. The flexibility tests show that the LEDs can be bent down to 1.5 cm curvature radius without significant degradation. Therefore, the replacement of the nano-phosphors used in the previous realization by relatively inexpensive micro-phosphors does not degrade the good mechanical flexibility of the white nanowire LEDs.
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45. Plasma-enhanced CVD growth of cubic and hexagonal diamond silicon nanowires with liquid-solid mixed catalysts for photovoltaic applications
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Wang, Weixi, STAR, ABES, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut Polytechnique de Paris, Jean-Luc Maurice, and Martin Foldyna
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Si hexagonal ,[CHIM.MATE] Chemical Sciences/Material chemistry ,Nanofils de silicium de petit diamètre ,Hexagonal phase ,PECVD ,Catalyseur composé ,TEM ,Mixed catalyst ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Small diameter SiNWs - Abstract
Silicon nanowires (SiNWs) are attracting an increasing attention due to their unique one-dimensional geometry with properties suitable for different optoelectronic applications. Recently, small diameter NWs (below 10 nm) have become the target due to predicted quantum size effects. Moreover, small diameter SiNWs with hexagonal diamond crystalline structure, which are predicted to have a direct bandgap that can be tuned by the diameter control, have been synthesized directly in a PECVD reactor. This thesis is dedicated to fabricating small diameter SiNWs with hexagonal phase using PECVD. The analysis on the previous work at LPICM has shown that hexagonal SiNWs were not obtained with a single Sn catalyst. We have demonstrated SiNW growth using evaporated SnCu mixed catalysts with a controlled composition for the first time, which leads to a core-shell structure on the top of SiNW with a crystalline Cu3Si core and a Sn-rich shell most probably liquid during the growth. The SiNWs have been grown through a combined VLS and VSS growth process. We have investigated the influence of the catalyst composition and PECVD conditions on the SiNW growth systematically and achieved ultra-dense (5.7 × 1010 /cm2) and ultra-thin silicon quantum nanowire arrays with average crystalline diameter of around 4 to 5 nm and with a narrow distribution. TEM observation showed that hexagonal phase can be obtained with a substrate temperature between 385 and 447 °C, and within a SiH4 partial pressure range from 0.026 to 0.068 mbar, on a Cu TEM grid, and on (100) Si wafer substrates using different SnCu compositions. The hexagonal phase appeared statistically rarely (usually with a yield of around 5 – 6%), with no particular growth condition except for the small diameter (with crystalline diameters from 4.0 to 7.2 nm). By replacing Sn with In element with similar properties in a mixed catalyst with Cu, dense SiNW arrays with an average diameter of 10.5 nm have been obtained, among which we found a hexagonal SiNW with crystalline diameter of 5 nm. In addition, the use of AuCu mixed catalysts has led to faster SiNW growth rate when compared to pure Au catalyst. Therefore, using mixed catalysts allows for a control of SiNW diameter (narrower distribution), length (growth rate), and density that cannot be obtained by using pure metal catalysts. Finally, PIN radial junction solar cells based on ultra-dense and thin SiNWs synthesized with SnCu and InCu co-catalysts have been fabricated successfully., Les nanofils de silicium bénéficient d’une attention accrue du fait de propriétés uniques liées à leur géométrie unidimensionnelle, propriétés qui intéressent différentes applications en opto-électronique. Récemment, des nanofils de très petit diamètre (inférieur à 10 nm) ont été l’objet de plusieurs études, car leurs propriétés prédites témoignent d’intéressants effets de confinement quantique. De plus, la structure hexagonale-diamant a été observée dans ce type de nanofils, et les calculs prédisent qu’ils auraient alors un gap direct, ajustable par contrôle du diamètre. Ces nanofils de silicium hexagonal ont été synthétisés lors d’une précédente étude au LPICM, dans un réacteur de dépôt chimique en phase vapeur assisté par plasma (PECVD). Le travail présenté ici a pour but la fabrication par PECVD de nanofils de très petit diamètre, avec la phase hexagonale diamant. Notre analyse des précédents travaux menés au LPICM montre que le catalyseur utilisé alors – nominalement de l’étain – comprenait en réalité un part de cuivre venant du substrat – une grille en cuivre de microscopie électronique en transmission (TEM). Nous avons donc démarré cette thèse par l’étude de catalyseurs mixtes SnCu de composition contrôlée. Ce type de catalyseur acquiert lors des traitements préliminaires une structure de type « cœur-coquille ». Lors de la croissance, le cœur devient du Cu3Si cristallin tandis que la coquille demeure un eutectique riche en étain, très certainement liquide à la température de croissance. Ce mode de croissance combine donc VLS (vapeur-liquide-solide) et VSS (Vapeur-solide-solide). Nous avons étudié de manière systématique l’influence de la composition du catalyseur et des conditions PECVD sur la croissance. Nous avons ainsi obtenu des tapis ultra-denses (5.7 × 1010 /cm2) de nanofils ultrafins (4-5 nm de diamètre cristallin). Nos observations TEM montrent que la phase hexagonale est présente, dans cette gamme de diamètres, pour toutes les conditions de croissance testées (température de 385 à 447 °C, pression de SiH4 de 0,026 à 0,068 mbar, sur grille TEM en Cu comme sur Si (100) et avec des catalyseurs de compositions en Sn et Cu variables). La phase hexagonale apparaît cependant avec une relativement faible probabilité (typiquement de 5 à 6%), sans condition de croissance particulière si ce n’est la faible taille (les valeurs des diamètres cristallins des nanofils hexagonaux sont entre 4.0 et 7.2 nm). En remplaçant l’étain par l’élément In, qui a des propriétés similaires, dans le catalyseur mixte avec Cu, nous obtenons également des réseaux denses de nanofils de Si, avec toutefois des diamètres plus grands pour une épaisseur de catalyseur égale. Dans un réseau de diamètre moyen de 10.5 nm, nous avons trouvé un nanofil de Si de 5 nm de diamètre avec une structure partiellement hexagonale. Nous avons également essayé le catalyseur mixte AuCu qui a donné des vitesses de croissance accrues, par rapport à l’Au pur. À l’issue de l’ensemble de ces expériences, nous pouvons affirmer qu’utiliser des catalyseurs mixtes, plutôt que des catalyseurs de métaux purs, permet un meilleur contrôle : du diamètre des nanofils (en autorisant des diamètres plus petits dans des distributions étroites) ; de leur longueur (par la vitesse de croissance), et de leur densité. Pour finir, nous avons fabriqué des cellules solaires à jonction radiale en silicium amorphe hydrogéné sur ce type de petits nanofils très denses, dopés p cette fois, synthétisés à partir des catalyseurs SnCu and InCu. Ces premières cellules apparaissent fonctionnelles.
- Published
- 2021
46. Fabrication and study of solar cell modules based on silicon nanowire based radial junction solar cells
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Al ghzaiwat, Mutaz, STAR, ABES, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Paris Saclay (COmUE), Pere Roca i Cabarrocas, and Martin Foldyna
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Solar cells ,VLS assisté par plasma ,Cellules solaires ,Couches minces ,Thin films ,Solar modules ,Modules solaires ,[PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Plasma-Assisted VLS ,Silicon nanowires ,Nanofils de silicium ,Jonction radiale ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Radial junctions - Abstract
In this thesis, we have used a low-temperature plasma-enhanced chemical vapor deposition (PECVD) reactor to fabricate Si nanowire radial junction solar mini-modules on 5x5 cm2 glass substrates with the assistance of the laser scribing technique for the series connection of the cells.We have used fluorine-doped tin oxide (FTO) deposited on soda-lime glass substrates (SLG) as a back contact as well as the source of the Sn catalyst which was formed by a direct reduction of FTO using a H2 plasma. Subsequently, p-type SiNWs were grown using plasma-assisted vapor liquid solid (VLS) process, followed by the deposition of intrinsic a-Si:H and n-type µc-SiOx:H layers to achieve pin radial junction solar cells. We have obtained an energy conversion efficiency of 6.3 % with an active area of solar cells of 0.126 cm2, which is to our knowledge, the highest efficiency obtained based on FTO layers as a source of Sn catalyst.Laser scribing was used to perform a selective removal of thin-film materials in order to fabricate minimodules. With laser scribing, a monolithic series connection between adjacent RJ SiNW solar cells on the same glass substrate was achieved. In particular, the laser scribing system has been used to perform selective removal of FTO thin-film and RJ SiNWs, which are commonly known as step P1 and P2, respectively, and to perform a final scribe to isolate the active region from the rest of the substrate. The transparent top ITO contact was sputtered and cell stripes were defined using the lift-off technique (step P3).We have carried out a detailed study of the P2 laser scribe obtained with either green (532 nm) or IR (1064 nm) laser setups. The power of the laser has to be controlled as it has a direct impact on the removal of SiNW RJs and it can damage the underneath FTO contact. We have found that the scribing using a green laser produces a partial melting outside the scribed spots, unlike the IR laser which provides a cleaner scribing and less crystallized material at the edges of scribed spots. Mapping of the scribed spots using Raman spectroscopy allowed analyzing the material composition within the scanned area inside the craters left by the laser pulses. We have demonstrated that the use of the IR laser is preferable for P2 scribing because it can provide a high-quality series connection between cells.Finally, the optimized 10 cm2 SiNW RJ mini-module has reached an energy conversion efficiency of 4.37 % with power generation of 44 mW, thanks to the improved P2 laser scribing and the dense Ag grid printed using the ink-jet method. This performance represents, to the best of our knowledge, the highest reported power generation for silicon nanowire-based solar modules on glass substrates., Dans cette thèse, nous avons utilisé un réacteur de dépôt chimique en phase vapeur assisté par plasma (PECVD) à basse température afin de fabriquer des minimodules à base de cellules solaires à jonction radiale (RJ SiNWs) sur des substrats de verre de 5x5 cm² en employant la gravure laser pour la mise en série des cellules.Nous avons utilisé une couche de 600 nm d’épaisseur de dioxyde d’étain dopée au fluor (FTO) déposée sur du verre sodocalcique (SLG). La couche de FTO sert à la fois de contact arrière pour le module et de source de catalyseur Sn une fois la couche de FTO réduite par un plasma de H2. Ensuite, on fait croître des SiNW dopés p par le procédé Vapor-Liquid-Solid (VLS) assisté par plasma, suivi d’un dépôt d’une couche de Si intrinsèque a-Si:H et d’une couche de Si dopée n µc-SiOx:H, afin d’obtenir une cellule solaire à jonction radiale PIN. Nous avons obtenu une efficacité énergétique de 6.3 % avec une surface active de 0.126 cm². C’est à notre connaissance l’efficacité la plus élevée obtenue en utilisant une couche de FTO comme source de catalyseur Sn.La gravure laser a été utilisée pour retirer localement des couches minces dans l’objectif de fabriquer des minimodules solaires. Grâce à la gravure laser, une connexion monolithique en série entre les cellules solaires à jonction radiale adjacentes a pu être accomplie. Dans cette thèse, la gravure laser a servi à retirer localement la couche de FTO ainsi que les RJ SiNWs, étapes appelées respectivement P1 et P2. On dépose ensuite une couche transparente d’oxyde d’indium-étain (ITO), servant de contact avant, par pulvérisation cathodique (étape P3), et on procède à la séparation en bandes par la technique « lift-off ». Nous avons mené une étude détaillée de l’étape P2 de gravure obtenue par un laser vert (532 nm) et IR (1064nm). La puissance du laser a un impact direct sur l’ablation des RJ SiNWs, et peut aussi endommager le contact arrière de la cellule. Nous avons déterminé que le laser vert entraîne une fonte partielle de matériau sur les bords de la zone gravée, contrairement au laser IR qui produit des gravures de meilleure qualité. La cartographie Raman des zones gravées permet une analyse des matériaux dans la zone étudiée, et a donné des indications sur la composition des résidus laissés par les impulsions laser. Nous avons démontré que l’utilisation du laser IR pour l’étape P2 de gravure est préférable. Elle permet d’avoir des connexions en série de haute qualité entre les cellules.Enfin, le mini-module optimisé de 10 cm² à base de RJ SiNWs a atteint un rendement de conversion énergétique de 4.37 % avec une puissance générée de 44 mW, grâce à l’amélioration de l’étape P2 et de l’impression par jet d’encre d’une grille dense d’Ag. À notre connaissance, cette puissance générée est la plus élevée rapportée pour des modules solaires à base de cellules à jonction radiale.
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- 2018
47. Modeling and characterization of materials and nanostructures for photovoltaic application
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Mrazkova, Zuzana, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Paris Saclay (COmUE), VŠB - Technical University of Ostrava, Pere Roca i Cabarrocas, Martin Foldyna, Kamil Postava, and STAR, ABES
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Solar cells ,Spectroscopic ellipsometry ,[SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic ,Optical properties ,Cellules solaires ,[SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,Multi-Layer optical models ,Modèles optiques multicouches ,Textures pyramidales ,Propriétés optiques ,Silicon nanowires ,Pyramidal textures ,Nanofils de silicium ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Ellipsométrie spectroscopique ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics - Abstract
Research in photovoltaics aims at lowering the price per watt of generated electrical power. Substantial efforts aim at searching for new materials and designs which can push the limits of existing solar cells. The recent development of complex materials and nanostructures for solar cells requires more effort to be put into their characterization and modeling. This thesis focuses on optical characterization, modeling, and design optimization of advanced solar cell architectures.Optical measurements are used for fast and non-destructive characterization of textured samples for photovoltaic applications. Surface textures enhance light-trapping and are thus desired to improve the solar cell performance. On the other hand, these textures make optical characterization more challenging and more effort is required for both, the optical measurement itself and subsequent modeling and interpretation of obtained data. In this work, we demonstrate that we are able to use optical methods to study the widely used pyramidal textures as well as very challenging randomly oriented silicon nanowire arrays.At first, we focused on the optical study of various pyramidal surfaces and their impact on the silicon heterojunction solar cell performance. We have found that vertex angles of pyramids prepared using various texturing conditions vary from the theoretical value of 70.52° expected from crystalline silicon. This change of the vertex angle is explained by regular monoatomic terraces, which are present on pyramid facets and are observed by atomic resolution transmission electron microscopy. The impact of a vertex angle variation on the thicknesses of deposited thin films is studied and the consequences for resulting solar cell efficiency are discussed. A developed optical model for calculation of the reflectance and absorptance of thin film multi-layers on pyramidal surfaces enabled a solar cell design optimization, with respect to a given pyramid vertex angle.In-situ Mueller matrix ellipsometry has been applied for monitoring the silicon nanowire growth process by plasma-enhanced vapor-liquid-solid method. We have developed an easy-to-use optical model, which is to our knowledge a first model fitting the experimental ellipsometric data for process control of plasma-assisted vapor-liquid-solid grown nanowires. The observed linear dependence of the silicon material deposition on the deposition time enables us to trace the fabrication process in-situ and to control material quality., La recherche sur le photovoltaïque vise à réduire le prix par watt de puissance électrique générée. Des efforts considérables sont menés pour rechercher de nouveaux matériaux et des conceptions qui repoussent les limites des cellules solaires existantes. Le développement récent de matériaux et nanostructures complexes pour les cellules solaires nécessite des efforts plus importants pour mener à bien leur caractérisation et leur modélisation. Cette thèse porte sur la caractérisation optique, la modélisation et l'optimisation de la conception d'architectures de cellules solaires de pointe.Les mesures optiques sont utilisées pour la caractérisation rapide et non destructive des échantillons texturés pour les applications photovoltaïques. Les textures de surface améliorent le piégeage de la lumière et sont donc souhaitées pour améliorer les performances des cellules solaires. D'autre part, ces textures rendent la caractérisation optique plus difficile et des efforts plus importants sont nécessaires non seulement pour la mesure optique elle-même mais également pour la modélisation et l'interprétation ultérieure des données obtenues. Dans ce travail, nous démontrons que nous sommes en mesure d'utiliser des méthodes optiques pour étudier les textures pyramidales très répandues ainsi que les réseaux de nanofils de silicium à orientation aléatoire dont l'analyse est très difficile.Premièrement, nous nous sommes concentrés sur l'étude optique de diverses surfaces pyramidales et de leur impact sur les performances des cellules silicium à hétérojonction. Nous avons constaté que les angles au sommet des pyramides, préparées à l'aide de différentes conditions de texturation, diffèrent de la valeur théorique de 70.52° attendue pour le silicium cristallin. Cette modification de l'angle au sommet est expliquée par la présence, sur les facettes pyramidales, de terrasses monoatomiques régulières, observées par microscopie électronique à transmission de résolution atomique. L'impact d'une variation de l’angle au sommet sur les épaisseurs des couches minces déposées est étudié et les conséquences sur l'efficacité des cellules solaires résultantes sont discutées. Un modèle optique développé pour le calcul de la réflectance et de l'absorption des couches minces en multicouches sur surfaces pyramidales a permis l’optimisation de la conception de la cellule solaire pour un angle au sommet pyramidal donné.L'ellipsométrie matricielle Mueller a été utilisée in-situ pour caractéiser le processus de croissance - par méthode vapeur-liquide-solide activée par plasma - des nanofils de silicium. Nous avons développé un modèle optique facile à utiliser, qui, à notre connaissance, est le premier modèle utilisant des données ellipsométriques expérimentales pour contrôler le procédé de croissance, en phase vapeur-liquide-solide assisté par plasma, des nanofils. La dépendance linéaire observée du dépôt de matériau de silicium avec le temps de dépôt nous permet de suivre le processus de fabrication in situ et de contrôler la qualité du matériau.
- Published
- 2017
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