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1. Characterization of inclined GaSb nanopillars by angle resolved Mueller polarimetry

Author

Søndergård E., Le Roy S., De Martino A., Kildemo M., Foldyna M., and Nerbø I.S.

Subjects
Physics, QC1-999
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.

Published
2010
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2. Profile characterization of diffraction gratings using angle-resolved polarimetric measurements

Author

Ben Hatit S., Foucher J., Licitra C., De Martino A., and Foldyna M.

Subjects
Physics, QC1-999
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
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8. Photonic Reflectors with Point Contact Approach for Cu(In,Ga)(S,Se)2 Solar Cells

Author

Balestrieri, M., Lakhdar Chaouche, S., Jimenez, C., Bellet, D., Foldyna, M., Roca I Cabarrocas, P., and Lincot, D.

Subjects
New Materials and Concepts for Cells and Modules, New Materials and Concepts for Photovoltaic Devices
Abstract

37th European Photovoltaic Solar Energy Conference and Exhibition; 20-24, In this work, we propose an innovative solution to fabricate a photonic back reflector layer prototype for Cu(In,Ga)(S,Se)2 (CIGS) solar cells that is optically rough, physically flat and electrically associated to molybdenum point contacts. This combination should lead to significant improvement in the efficiency of CIGS solar cells and favor the use of thinner CIGS layers. The nanostructured pattern is obtained using polystyrene beads self-assembly, followed by Ag evaporation and polystyrene beads lift-off. Stacks comprising a nanostructured multilayer of silver, molybdenum and an alumina layer deposited conformally by ALCVD, are successfully stacked. The optical characterization of the samples (in air) during the last steps before polishing, including angular resolved measurements, shows that these layers present very large haze factors (around 50%) over a large region of the solar spectrum. Preliminary attempts to planarize the substrate and to reveal the point contacts by chemical etching are reported.

Published
2020
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12. Magneto-optic vector magnetometry of CoFeCrSiB amorphous ribbons

Author

Zivotsky, O., Postava, K., Foldyna, M., Pistora, J., and Kraus, L.

Subjects
Physics
Abstract

A magneto-optic method suitable for investigation of soft magnetic ribbons is proposed that combines the internal magnetic field induced by a current flowing through ribbon axis with the external magnetic field generated by an air cool coil. The method is applied to study magnetic properties of CoFeCrSiB amorphous ribbons showing asymmetric giant magnetoimpedance effects.

Published
2006

13. Characterization of inclined GaSb nanopillars by Mueller matrix ellipsometry.

Author

Nerbø, I. S., Le Roy, S., Foldyna, M., Kildemo, M., and Søndergård, E.

Subjects
GALLIUM, ANTIMONY, ELLIPSOMETRY, SPUTTERING (Physics), ION bombardment
Abstract

Inclined GaSb nanopillars prepared by low energy ion sputtering with oblique ion beam incidence have been characterized by two different Mueller matrix ellipsometric tools. The optical properties of the nanopillars were found to be well described by a uniaxial anisotropic graded effective medium model. The pillar height and inclination angle were determined by fitting the parameters of the effective medium model to spectroscopic (1.44–2.88 eV) Mueller matrix measurements at multiple azimuth sample orientations. A set of different samples with various average pillar height and inclination angle was studied; results from the optical characterization correspond well with those from scanning electron microscopy analysis. For samples with nanopillars inclined by 45° or less, the height could be determined from a single Mueller matrix measurement at only one azimuth orientation, allowing real-time in situ observation of the formation. The nanopillars were also studied using a single wavelength angle resolved Mueller polarimeter, which also can be used to determine height and inclination of the pillars, in addition to validating the optical model over a wide range of incident and azimuth angles. [ABSTRACT FROM AUTHOR]

Published
2010
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14. Comprehensive analyses of core–shell InGaN/GaN single nanowire photodiodes

Author

Zhang, H, primary, Guan, N, additional, Piazza, V, additional, Kapoor, A, additional, Bougerol, C, additional, Julien, F H, additional, Babichev, A V, additional, Cavassilas, N, additional, Bescond, M, additional, Michelini, F, additional, Foldyna, M, additional, Gautier, E, additional, Durand, C, additional, Eymery, J, additional, and Tchernycheva, M, additional

Published
2017
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16. Flexible Optoelectronic Devices Based on Nitride Nanowires Embedded in Polymer Films

Author

Tchernycheva, M., primary, Guan, N., additional, Dai, X., additional, Zhang, H., additional, Piazza, V., additional, Kapoor, A., additional, Bougerol, C., additional, Mancini, L., additional, Julien, F.H., additional, Lu, L., additional, Morassi, M., additional, Gogneau, N., additional, Harmand, J.-C., additional, Largeau, L., additional, Foldyna, M., additional, Eymery, J., additional, and Durand, C., additional

Published
2017
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19. Kelvin Probe Force Microscopy Study of Electric Field Homogeneity in Epitaxial Silicon Solar Cells Cross-Section

Author

Narchi, P., Picardi, G., Cariou, R., Foldyna, M., Prod'homme, P., and Roca I Cabarrocas, P.

Subjects
Silicon-based Thin Film and Silicon-Heterojunction Solar Cells and Modules, THIN FILM SOLAR CELLS AND MODULES
Abstract

31st European Photovoltaic Solar Energy Conference and Exhibition; 1026-1029, Using Kelvin probe force microscopy, cross-section measurements along the PIN junction of an epitaxial silicon solar cell were performed under operating conditions (illumination, voltage bias). Surface potential profiles show coherent behaviors with theoretical expectations when the device is under increasing illumination intensity, increasing voltage bias, or under illumination at different wavelengths. Using measurements under voltage bias, we propose a methodology to investigate the electric field homogeneity along the PIN junction. It is shown that the electric field is not homogeneous for the cell measured and it is suggested that this might be due either to preparation steps or to inhomogeneous defective layer along the PIN junction.

Published
2015
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20. Photonic nanostructures for advanced light trapping in thin crystalline silicon solar cells

Author

Trompoukis , C., ABDO , I., Cariou , R., COSNIER , T., Cosme , I., Chen , W., Depauw , V., Deparis , O., Dmitriev , A., Drouard , Emmanuel, Foldyna , M., Garcia-Caurel , E., Gordon , I., Heidari , B., HERMAN , A., Lalouat , Loïc, Lee , K., Liu , Jia, LODEWIJKS , K., Mandorlo , Fabien, IMEC ( IMEC ), Catholic University of Leuven ( KU Leuven ), Departement Elektrotechniek - ESAT [leuven], Katholieke Universiteit Leuven ( KU Leuven ), 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, Service d'Optique et Acoustique, Université Libre de Bruxelles [Bruxelles] ( ULB ), 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 ), Laboratoire Interdisciplinaire Carnot de Bourgogne ( LICB ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University [Shenyang], and INL - Photovoltaïque ( INL - PV )

Subjects
[ SPI.MAT ] Engineering Sciences [physics]/Materials, [ SPI ] Engineering Sciences [physics], [ SPI.NANO ] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [ SPI.OPTI ] Engineering Sciences [physics]/Optics / Photonic, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; no abstract

Published
2015

21. Attaining 46% Utilization of the AM1.5G Photons Impinging per Area on a 400nm Thick nc-Si Cell Using Light Trapping Nanoelement-Array Light Structures

Author

Nam, W.J., Dornstetter, J.-C., Foldyna, M., Roca I Cabarrocas, P., Gray, Z., Waggoner, S., Cakmak, A.O., Neidich, D., and Fonash, S.J.

Subjects
Silicon-based Thin Film and Silicon-Heterojunction Solar Cells and Modules, THIN FILM SOLAR CELLS AND MODULES
Abstract

31st European Photovoltaic Solar Energy Conference and Exhibition; 1315-1320, We report on a design and a nc-Si material combination, that together, mitigate against absorber defect formation, and allow the utilization of 46% of the photons with E ≥1.1eV impinging on a 400nm thick nc- Si absorber. This utilization percentage can be compared against our previous 49% result for 700nm nc-Si nanostructured cells. The currently fabricated cells have photocurrents that are hampered by back Ag coverage, TCO series resistance, and poor fill factors. FIB FESEM studies show these latter two issues are not due to defects in the nc-Si, a problem which had dominated in our previous work but which has been overcome by the use of our newest design and LPICM-CNRS nc-Si material. This FIB cross-section FESEM work also shows the very solvable back Ag non-uniformity. Light J-V as well as dark J-V characterization allow the quantification of the reverse bias dependence and poor fill factor behavior which are shown to have their origins in these Ag deposition discontinuities as well as in series resistance issues. Computer studies have guided our work in developing this ultra-thin nc-Si light and carrier collection management (LCCM) design. We discuss this modeling and our remaining problems, solutions, and expectations for our LCCM design.

Published
2015
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22. Improving the Performance of Thin Film Radial Junction Solar Cells

Author

Misra, S., Yu, L., Foldyna, M., and Roca I Cabarrocas, P.

Subjects
NEW MATERIALS AND CONCEPTS FOR SOLAR CELLS AND MODULES, New Materials and Concepts for Cells
Abstract

29th European Photovoltaic Solar Energy Conference and Exhibition; 46-49, Due to a unique structure, a silicon nanowire matrix provides natural light trapping and anti-reflection effects suitable for photovoltaic applications. Thus depositing thin film silicon directly on top of them and forming radial junctions is a promising approach for a new generation of efficient solar cells. Apart from the light trapping, their major advantage is decoupling of the light absorption from the carrier collection direction. This allows the use of very thin active layer, providing more efficient collection in materials with low minority carrier diffusion lengths and also minimizes the light-induced degradation. It has been found that the density of radial junctions is a very important parameter for controlling the device performances. By optimizing the nanowire density, we have demonstrated 8.1 % efficiency for PIN hydrogenated amorphous silicon (a-Si:H) solar cells deposited directly on the TCO coated glass with only 100 nm of active layer thickness. We have adopted two different approaches to improve the short-circuit current density and open-circuit voltage. Firstly, replacing n-type a-Si:H by more transparent amorphous silicon oxide has enhanced the blue response of the solar cell. Secondly, we have shown that a p-type a-Si:H coating on the crystalline silicon nanowire, before depositing the intrinsic layer, is very effective in reducing the nanowire surface recombination and consequently increasing the open-circuit voltage.

Published
2014
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23. Nanophotonics for ultrathin crystalline silicon photovoltaics: When photons (actually) meet electrons

Author

Depauw, V., ABDO, I., Boukhicha, R., Cariou, R., Chen, W., Cosme, I., Deparis, O., Dmitriev, A., Drouard, Emmanuel, El Daif, Ounsi, Foldyna, M., Garcia-Caurel, E., Heidari, B., HERMAN, A., Lalouat, Loic, Seassal, Christian, Liu, Jia, LODEWIJKS, K., Mandorlo, Fabien, Orobtchouk, Regis, IMEC (IMEC), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), 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 des Sciences de l'Ingénieur Appliquées à la Mécanique et au génie Electrique (SIAME), Université de Pau et des Pays de l'Adour (UPPA), Service d'Optique et Acoustique, Université libre de Bruxelles (ULB), 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), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), INL - Hétéroepitaxie et Nanostructures (INL - H&N), INL - Photovoltaïque (INL - PV), 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), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI]Engineering Sciences [physics], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract

22-26 sept; International audience; no abstract

Published
2014

26. Sum decomposition of Mueller-matrix images and spectra of beetle cuticles

Author

Arwin, Hans, Magnusson, Roger, Garcia-Caurel, Enric, Fallet, C., Järrendahl, Kenneth, Foldyna, M., De Martino, A., Ossikovski, R., Arwin, Hans, Magnusson, Roger, Garcia-Caurel, Enric, Fallet, C., Järrendahl, Kenneth, Foldyna, M., De Martino, A., and Ossikovski, R.

Abstract

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.

Published
2015
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27. Magneto-optic vector magnetometry of CoFeCrSiB amorphous ribbons.

Author

Zˇivotský, O., Postava, K., Foldyna, M., Pisˇtora, J., and Kraus, L.

Subjects
MAGNETOOPTICS, MAGNETIC fields, PROPERTIES of matter, ELECTRIC currents, HYSTERESIS loop
Abstract

A magneto-optic method suitable for investigation of soft magnetic ribbons is proposed that combines the internal magnetic field induced by a current flowing through the ribbon axis with the external magnetic field generated by an air coil. The method eliminates effects of demagnetizing factor and shape anisotropy on measured hysteresis loops. Both in-plane magnetization components are measured by means of magneto-optic vector magnetometry. The method is applied to study magnetic properties of CoFeCrSiB amorphous ribbons showing asymmetric giant magnetoimpedance effects. A coherent rotation of magnetization and in-plane easy axis inclined from the ribbon axis is observed. It corresponds to helical magnetic anisotropy originating from the preparation processes. [ABSTRACT FROM AUTHOR]

Published
2006
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35. Performance analysis of AlxGa1-xAs/epi-Si(Ge) tandem solar cells: a simulation study.

Author

Lachaume, R., Cariou, R., Decobert, J., Foldyna, M., Hamon, G., i Cabarrocas, P. Roca, Alvarez, J., and Kleider, J.-P.

Abstract

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 20μm 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 (∼5μm). 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. [ABSTRACT FROM AUTHOR]

Published
2015
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38. Effects of Roughness on Scatterometry Signatures

Author

Foldyna, M., primary, Germer, T. A., additional, Bergner, B. C., additional, Seiler, David G., additional, Diebold, Alain C., additional, McDonald, Robert, additional, Chabli, Amal, additional, and Secula, Erik M., additional

Published
2011
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