Author: "Chantal Fontaine" - Searchworks@Jio Institute Digital Library Search Results

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163 results on '"Chantal Fontaine"'

1. Transfer of an AlGaAs/GaAs crystalline Bragg mirror from a GaAs substrate to a fused silica substrate by direct bonding

Author: Victor Hui, Agathe André, Alexandre Arnoult, Pascal Besson, Christophe Dubarry, Chantal Fontaine, Frank Fournel, Victor Lumineau, Christelle Navonne, Laurent Pinard, and Raffaele Flaminio
Published: 2022

2. Photoluminescence in n and p modulation-doped GaInNAs/GaAs quantum wells.

Author: Mükremin Yilmaz, Y. Sun, Naci Balkan, Bülent Ulug, A. Ulug, M. Sopanen, O. Reentilä, M. Mattila, Chantal Fontaine, and A. Arnoult
Published: 2009
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3. In-situ magnification inferred curvature measurement applied to dilute bismide growth

Author: Alexandre Arnoult, Colin, J., Cornille, C., Louarn, K., Marigo-Lombart, L., Maxime Levillayer, Guilhem Almuneau, Chantal Fontaine, Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Équipe Photonique (LAAS-PHOTO), Almuneau, Guilhem, Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: [SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic, [SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, [SPI.MAT] Engineering Sciences [physics]/Materials, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract: International audience; Probing in real time thin film processes is an efficient way to unravel the impact of key parameters as this approach offers a direct insight on the involved mechanisms. MBE has benefited from a large number of in-situ techniques like RHEED, reflectivity, or optical thermometry. Despite the direct measurement of stress in the growing layers that they allow, curvature measurement tools based on laser deflectometry have not been widely adopted by the MBE community, due to intrinsic technological limitations. We have developed a novel curvature measurement technique, named Magnification Inferred Curvature (MIC), that overcomes these limitations. We will explain the principle of the measurement and illustrate its unique capabilities with a few selected examples, focusing on the GaAs1-xBix alloy. Keywords: in-situ, curvature, stress, dilute bismide
Published: 2021

4. Picosecond photodiffraction in semiconductor multiquantum wells and microcavities.

Author: Jean-Louis Iehl, Rodolphe Grac, Luc le Gratiet, Véronique Bardinal, Rainer Buhleier, Elena Bedel-Pereira, Chantal Fontaine, Michel Pugnet, and Jacques-Henry Collet
Published: 1997
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5. Development of 1 eV InGaAsN PIN subcell for MJSC integration and space application

Author: Sophie Duzellier, Guilhem Almuneau, Laurent Artola, Chantal Fontaine, Inès Massiot, Corinne Aicardi, T. Nuns, S. Parola, Alexandre Arnoult, Maxime Levillayer, Christophe Inguimbert, Hélène Carrère, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Micro électronique, Composants, Systèmes, Efficacité Energétique (M@CSEE), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Centre National d'Études Spatiales [Toulouse] (CNES), IEEE, Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: MJSC, 010302 applied physics, Materials science, Annealing (metallurgy), Analytical chemistry, 02 engineering and technology, Substrate (electronics), Nitride, 021001 nanoscience & nanotechnology, 01 natural sciences, Temperature measurement, [SPI.MAT]Engineering Sciences [physics]/Materials, Gallium arsenide, dilute nitride, chemistry.chemical_compound, Pulmonary surfactant, Molecular beam epitaxial growth, chemistry, 0103 physical sciences, InGaAsN, space applications, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, 1eV cell, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 0210 nano-technology
Abstract: International audience; This paper reports on the optimization of 1eV dilute nitride solar cells growth conditions. InGaAsN cells were grown by MBE under different conditions (V/III ratio, substrate temperature, surfactant) and were processed without post-growth annealing. Characterization results suggest that the V/III ratio should be kept above 10 and that using Bi as a surfactant does not improve the cell performances. Our best InGaAsN cells exhibit Jsc and Voc values of 7.9 mA/cm 2 and 0.375 V respectively, under AM0> 870 nm and without ARC.
Published: 2020

6. Effects of Thermal Annealing and Selective Chemical Etching on Structural and Optical Properties of GaAsBi Epilayer with Droplet Systems

Author: Chantal Fontaine, Tulin Erucar, Alexandre Arnoult, Ayse Erol, Omer Donmez, and Kamuran Kara
Subjects: Materials science, Photoluminescence, Annealing (metallurgy), Atomic force microscopy, Electrostatic force microscope, Biomedical Engineering, Analytical chemistry, Bioengineering, General Chemistry, Condensed Matter Physics, Isotropic etching, Optical quality, General Materials Science, Molecular beam epitaxy
Abstract: A GaAs1-xBix layer was grown by molecular beam epitaxy (MBE) with a low Bi content (2.3%) on GaAs maintaining the substrate at a non-rotating state and was then annealed at 750 °C, 800 °C and 850 °C. Each sample that was covered with droplets was investigated by using the Atomic Force Microscopy (AFM), Electrostatic Force Microscopy (EFM) and Photoluminescence (PL) techniques. The surface properties of the GaAs1-xBix layer were investigated by AFM and observed to have a droplet system, which was composed of a donut and a tail. The optical quality of the samples was enhanced after thermal annealing up to 800 °C, and the maximum PL intensity was obtained at 750 °C. AFM images revealed that the shape of the droplet and tail changed with increasing annealing temperature. EFM images revealed a phase separation on the surface droplet system. To explore the nature of the droplets, previously claimed to be made of Ga and/or Bi, and their effect on PL spectrum, a chemical etch procedure was carried out by using diluted solutions of H₂SO₄ and/or HCl. We showed that droplets may be efficiently removed from the surface, and PL intensity could be improved by using a proper sequence of chemical etching procedures. Furthermore, the presence of two different phases for the droplet-system observed by EFM was also confirmed by the selective etching procedure.
Published: 2019

7. Thickness limitation of band to band tunneling process in InGaAs/GaAsSb type-II tunnel junctions designed for multijunction solar cells

Author: Kevin Louarn, Inès Massiot, Alexandre Bounouh, François Piquemal, Nicolas Cavassilas, Yann Claveau, Ludovic Marigo-Lombart, Alexandre Arnoult, Chantal Fontaine, Guilhem Almuneau, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), 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), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Laboratoire National de Métrologie et d'Essais [Trappes] (LNE ), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), 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), Équipe Photonique ( LAAS-PHOTO ), Laboratoire d'analyse et d'architecture des systèmes [Toulouse] ( LAAS ), Centre National de la Recherche Scientifique ( CNRS ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Institut National Polytechnique [Toulouse] ( INP ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Toulouse III - Paul Sabatier ( UPS ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Institut National Polytechnique [Toulouse] ( INP ), 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 ), Service Techniques et Équipements Appliqués à la Microélectronique ( LAAS-TEAM ), Laboratoire National de Métrologie et d'Essais [Trappes] ( LNE ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), and Laboratoire d'Intégration des Systèmes et des Technologies (LIST)
Subjects: Materials science, [ SPI.MAT ] Engineering Sciences [physics]/Materials, Energy Engineering and Power Technology, 02 engineering and technology, Multijunction photovoltaic cell, Computer Science::Computational Geometry, Epitaxy, 7. Clean energy, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Condensed Matter::Materials Science, Tunnel junction, Condensed Matter::Superconductivity, 0103 physical sciences, Materials Chemistry, Electrochemistry, Chemical Engineering (miscellaneous), Tunneling current, Electrical and Electronic Engineering, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Quantum tunnelling, 010302 applied physics, Local density of states, business.industry, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Heterojunction, 021001 nanoscience & nanotechnology, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, [ SPI.NANO ] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [ SPI.OPTI ] Engineering Sciences [physics]/Optics / Photonic, 0210 nano-technology, business, Molecular beam epitaxy
Abstract: International audience; This article reports on the impact of the thickness and/or the composition on the performance of type-II n+ InGaAs/p+ GaAsSb tunnel junctions. The InGaAs/GaAsSb staggered band-offset heterojunction is expected to improve tunneling properties. Devices have been grown by molecular beam epitaxy with various thicknesses and/or Sb and In concentrations. For thin elastically strained type-II tunnel junctions, the electrical characteristics exhibit degraded transport performances compared to the reference p+ GaAs/n+ GaAs tunnel junction structures, while much better tunneling peak currents are achieved with strain-relaxed thick type-II tunnel junctions. Based on a theoretical analysis of the local density of states and the band-edges profiles of the type-II tunnel junctions, we propose a suitable design for type-II tunnel junctions with high tunneling current density toward their use in multi-junction solar cells.
Published: 2019

8. Selective oxidation of AlGaAs for confinement in III-V photonic devices

Author: Guilhem Almuneau, Stéphane Calvez, Gael Lafleur, Chantal Fontaine, Alexandre Arnoult, Antoine Monmayrant, Henri Camon, Olivier Gauthier-Lafaye, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2018

9. Effect of low and staggered gap quantum wells inserted in GaAs tunnel junctions

Author: Nicolas Cavassilas, Kevin Louarn, Ludovic Marigo-Lombart, Yann Claveau, François Piquemal, Chantal Fontaine, Alexandre Bounouh, Alexandre Arnoult, Guilhem Almuneau, Laboratoire National de Métrologie et d'Essais [Trappes] (LNE ), Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), 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), Brussels Photonics Team [Bruxelles] (B-PHOT), Vrije Universiteit Brussel (VUB), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Département Métrologie Instrumentation & Information (DM2I), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), 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)-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)-Université Paris-Saclay, ANR-14-CE26-0020,PLATOFIL,PLAteforme phoTOnique à base de nanoFILs(2014), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), and Laboratoire d'Intégration des Systèmes et des Technologies (LIST)
Subjects: Materials science, Acoustics and Ultrasonics, quantum well, 02 engineering and technology, 7. Clean energy, 01 natural sciences, SEMICONDUCTORS, law.invention, tunnel junction, Condensed Matter::Materials Science, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], law, Tunnel junction, molecular beam epitaxy, Condensed Matter::Superconductivity, 0103 physical sciences, DIODES, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Quantum well, Diode, 010302 applied physics, interband tunneling, Condensed Matter::Other, business.industry, Transistor, Doping, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Heterojunction, multi-junction solar cell, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, photovoltaics, Semiconductor, Optoelectronics, 0210 nano-technology, business, Molecular beam epitaxy
Abstract: International audience; In this article, we investigate the impact of the insertion of either a type I InGaAs or a type II InGaAs/GaAsSb quantum well on the performances of MBE-grown GaAs tunnel junctions (TJs). The devices are designed and simulated using a quantum transport model based on the non-equilibrium Green's function formalism and a 6-band k.p Hamiltonian. We experimentally observe significant improvements of the peak tunneling current density on both heterostructures with a 460-fold increase for a moderately doped GaAs TJ when the InGaAs QW is inserted at the junction interface, and a 3-fold improvement on a highly doped GaAs TJ integrating a type II InGaAs/GaAsSb QW. Thus, the simple insertion of staggered band lineup heterostructures enables us to reach a tunneling current well above the kA cm−2 range, equivalent to the best achieved results for Si-doped GaAs TJs, implying very interesting potential for TJ-based components, such as multi-junction solar cells, vertical cavity surface emitting lasers and tunnel-field effect transistors.
Published: 2018

10. Bismuth content dependence of the electron spin relaxation time in GaAsBi epilayers and quantum well structures

Author: Chantal Fontaine, Alexandre Arnoult, D. Lagarde, Thierry Amand, Hélène Carrère, Fabian Cadiz, Simone Mazzucato, Xavier Marie, F Beato de le Salle, Henri Lehec, Sawsen Azaizia, Andrea Balocchi, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Équipe Photonique (LAAS-PHOTO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: 010302 applied physics, Range (particle radiation), Materials science, Optical orientation, Condensed matter physics, chemistry.chemical_element, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Electronic, Optical and Magnetic Materials, Bismuth, [SPI.MAT]Engineering Sciences [physics]/Materials, Condensed Matter::Materials Science, chemistry, Condensed Matter::Superconductivity, 0103 physical sciences, Materials Chemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Electrical and Electronic Engineering, 0210 nano-technology, Nuclear Experiment, Spin relaxation, Quantum well
Abstract: International audience; Time-resolved optical orientation experiments have been performed in dilute bismide structures. Bulk layers with bismuth fractions in the range 1%–3.8% and quantum wells with bismuth fractions in the range 2.4%–7% were investigated. A clear decrease of the electron spin relaxation time is evidenced in both cases when the bismuth content increases. These results can be well interpreted by the increased efficiency of the spin relaxation mechanisms due to the bismuth induced larger spin-orbit interaction in these alloys.
Published: 2018

11. Tampon graduel et jonction tunnel de type II relaxés sur GaAs pour sous cellules solaires métamorphiques à 1 eV

Author: Kevin Louarn, Chantal Fontaine, Alexandre Arnoult, Yann Claveau, Ludovic Marigo-Lombart, Inès Massiot, Jonathan Colin, Clara Cornille, Leite, E., Laurent Lombez, Nicolas Cavassilas, François Piquemal, Alexandre Bounouh, Guilhem Almuneau, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), 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), Institut de Recherche et Développement sur l'Energie Photovoltaïque (IRDEP), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Laboratoire National de Métrologie et d'Essais [Trappes] (LNE ), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)
Subjects: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic
Abstract: National audience; La technologie des cellules solaires tandem (MJSCs) GaAs (1.42 eV)/GaInP (1.87 eV) sur substrat GaAs est très mature, et l'ajout de souscellules solaires de plus petit gap à cette structure bien maîtrisée a permis d'obtenir de très hauts rendements audelà de 40 %. Les alliages GaInAsN accordés sur GaAs (rendement de 43.5% [1]), GaInAs métamorphique (rendement de 44.4 % [2]) ainsi que le collage par "waferbonding" de souscellules fabriquées sur InP (rendement de 46% [2]) ont jusqu'ici été exploités. Dans l'optique de dépasser cette valeur record dans des cellules solaires métamorphiques, la maîtrise d'un matériau à 1 eV ayant de bonnes propriétés structurales et optoélectroniques est indispensable, et constitue un défi majeur pour la filière des MJSCs sur substrat GaAs. Nous visons à exploiter un alliage GaAsBi, avec une concentration de bismuth de 7%. En effet, cet alliage présente un désaccord de maille avec le GaAs plus faible (0.6%) que l'alliage Ga 0.69 In 0.31 As (2.2%) pour atteindre 1eV. De ce fait, la couche graduelle métamorphique AlGaInAs élaborée avant l'absorbeur 1eV qui ne contiendra que 15% d'indium au lieu de 35%, pourra être plus fine et sera de meilleure qualité structurale. Pour encore améliorer les performances de ces souscellules, il est aussi nécessaire de disposer de jonctions tunnel (JT) de hautes performances permettant la connexion électrique entre les souscellules [3]. Nous proposons ici une géométrie originale de JT et présentons les résultats obtenus. Nous démontrons la fabrication par Epitaxie par Jets Moléculaires (EJM) d'une JT AlGaInAs/AlGaAsSb hautes performances intégrée au tampon graduel relaxé réalisant l'accord de maille du GaAsBi (xBi =7%), comme présenté sur la Figure 1. Cette solution a été développée à partir d'un travail expérimental et théorique autour des hétérojonctions tunnel de type II GaAsSb/GaInAs, qui sera donc aussi détaillé. Comme preuves de concept, la croissance de cellules solaires métamorphiques GaInAs (x In =11%) (1.25 eV) et GaAsSbN (1 eV) a été réalisée et les composants sont en cours de fabrication. Les premiers résultats obtenus sur ces composants seront discutés. Références: [1] Sabnis, V., Yuen, H., Wiemer, M. (2012,). Highefficiency multijunction solar cells employing dilute nitrides.
Published: 2017

12. Comparaison d'absorbeurs à 1 eV à base de nitrure dilué accordés en maille sur GaAs: GaInAsN, GaAsSbN et GaInAsN(Bi)

Author: Inès Massiot, Kevin Louarn, Chantal Fontaine, Sawsen Azaizia, Alexandre Arnoult, Clara Cornille, Jonathan Colin, Leite, E., Lombez, L., Bounouh, A., Andrea Balocchi, Hélène Carrère, Piquemal, F., Guilhem Almuneau, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Institut de Recherche et Développement sur l'Energie Photovoltaïque (IRDEP), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Laboratoire National de Métrologie et d'Essais [Trappes] (LNE ), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic
Abstract: National audience; La cellule solaire à multijonction reste aujourd'hui l'approche la plus performante en terme d'efficacité de conversion photovoltaïque. Ces cellules qui sont commercialisées avec des rendements de 40 % sont réalisées à base de GaInP(1,9eV)/GaAs(1,42eV)/Ge(0,66eV). Cependant un matériau avec un gap autour de 1eV permettrait soit de remplacer le Ge avec un gain sur le rendement, et/ou permettre d'améliorer les cellules à 4 ou 5 jonctions grâce à une bande d'absorption optimale. Différentes solutions ont été proposées pour réaliser des alliages dilués à base d'azote, d'antimoine et/ou de bismuth avec un gap de 1eV et accordés en maille au substrat GaAs ou Ge. L'épitaxie de ces alliages GaInAsN, GaAsSbN et GaAsBiN en couche épaisse reste complexe et donc leurs propriétés structurales, électriques et optiques difficiles à maîtriser. Sur la base de notre savoirfaire au LAAS sur les nanostructures quantiques à base de ces matériaux, nous avons étudié la croissance par épitaxie par jets moléculaires de plusieurs types d'alliages (GaInAsN, GaAsSbN et GaInAsN avec surfactant Bi) accordés en maille sur GaAs pour les applications photovoltaïques dans le proche infrarouge. Notamment nous avons optimisé les conditions de croissance de ces matériaux grâce au contrôle insitu des contraintes et de caractérisations structurales (Diffraction rayons X) et optiques (Photoluminescence résolue en temps) exsitu. En particulier, l'impact des propriétés surfactantes de l'antimoine et du bismuth sur les propriétés structurales, électroniques et optiques du Ga(In)AsN sera présenté en s'appuyant notamment sur la caractérisation de cellules solaires intégrant ces différents matériaux absorbeurs. Ce travail a bénéficié du support financier du projet EMRPEURAMET SolCell et de l'ANRTCIFRE; et a bénéficié du support technique de la centrale de technologie du LAASCNRS du réseau RENATECH.
Published: 2017

13. Jonctions tunnel AlGaAsSb/AlGaInAs accordées et relaxées sur substrat GaAs pour les applications photovoltaïques

Author: Kevin Louarn, Yann Claveau, Alexandre Arnoult, Chantal Fontaine, Jonathan Colin, Clara Cornille, Inès Massiot, Ludovic Marigo-Lombart, François Piquemal, Alexandre Bounouh, Nicolas Cavassilas, Guilhem Almuneau, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire National de Métrologie et d'Essais [Trappes] (LNE ), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic
Abstract: Résumé pour une présentation orale / sur poster; National audience; Les Jonctions Tunnel (JT) sont des composants très importants pour les cellules solaires multi-jonction, puisqu'elles assurent la connexion électrique en série entre les différentes sous-cellules. Récemment, il a été fabriqué par EPVOM des JTs AlGaAs:C/GaAs:Te et AlGaAs:C/GaInP:Te atteignant des densités de courant pic J pic records de 10 kA/cm² sur substrat GaAs [1], en remplaçant le dopant N usuel Si par du Te et permettant ainsi d'obtenir les forts niveaux de dopages nécessaires pour augmenter la probabilité d'effet tunnel dans le composant. Nous avons travaillé sur une autre approche pour obtenir des JT de "hautes" performances, et ne nécessitant pas des dopages aussi forts : il s'agit de profiter des offsets de bandes de l'hétérojonction AlGaAsSb/AlGaInAs de type II pour augmenter la probabilité d'effet tunnel.
Published: 2017

14. Pseudomorphic and metamorphic (Al)GaAsSb/(Al)InGaAs tunnel junctions for GaAs based Multi-Junction Solar Cells

Author: Kevin Louarn, Yann Claveau, Alexandre Arnoult, Chantal Fontaine, Jonathan Colin, Clara Cornille, François Piquemal, Alexandre Bounouh, Nicolas Cavassilas, Guilhem Almuneau, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), 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), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Laboratoire National de Métrologie et d'Essais [Trappes] (LNE ), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), 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), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), and Laboratoire d'Intégration des Systèmes et des Technologies (LIST)
Subjects: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic
Abstract: International audience; Aim and approach-Tunnel Junctions (TJs) are key devices for monolithic Multi-Junction Solar Cells (MJSCs), in which they ensure the series interconnection between the subcells. For GaAs based MJSCs, very low resistive (with peak tunneling current density J peak up to 10 kA/cm²) AlGaAs:C/GaInP:Te or AlGaAs:C/GaAs:Te have been recently developed by MOVPE using Te instead of Si as N-dopant making it possible to get the heavily doping levels needed for tunneling optimization [1]. In this work, we investigate an alternative to this approach. The tunneling probability is increased through the engineering of band-offset thanks to the use of a type II (Al)GaAsSb/(Al)InGaAs staggered heterojunction. Such TJs are suitable for both lattice-matched and metamorphic MJSCs. Scientific innovation and relevance – MBE was used to grow pseudomorphic and metamorphic (Al)GaAsSb/(Al)InGaAs TJs (5% to 10 % In and Sb contents) on GaAs substrate, where Aluminium enables to limit light absorption in the TJ. We have experimentally and theoretically investigated the role of the layer thicknesses on the tunneling mechanisms to propose TJ heterostructure designs suitable for lattice-matched MJSCs and metamorphic MJSCs. Preliminary results and conclusions-For relatively thin [10 to 30 nm] type II TJs, the incorporation of Sb/In in the GaAs TJ is actually degrading the electrical performances, with J peak decreasing from 180 A/cm² for simple GaAs TJ to 70 A/cm² for GaAs 0.95 Sb 0.05 /In 0.05 Ga 0.95 As TJs. On the other hand, thicker 100 nm (Al)GaASb/(Al)InGaAs TJs present the expected tunneling current density increase with J peak close to 1000 A/cm². It worths to note that such thick TJs lead to strain/relaxation issues that could be detrimental for lattice-matched MJSCs but beneficial for metamorphic MJSCs. The origin of this difference in behavior is under investigation both using a semi-classical model [2] and a Non Equilibrium Green's Function based quantum model [3]. First simulations suggest that it originates from a balance between quantum confinement and type II-related tunneling probability enhancement. Based on these results, we are developing GaAs/InGaAs/GaAsSb/GaAs TJs suitable for lattice-matched MJSCs with preliminary measurements showing a thousand-fold increase of the peak tunneling current. Complementary, we are studying the relaxation mechanisms of (Al)Ga(In)As(Sb) alloys using in-situ MBE stress measurements in order to optimize the growth of metamorphic (Al)GaAsSb/(Al)InGaAs TJs.
Published: 2017

15. Low-loss buried AlGaAs/AlOx waveguides using a quasi-planar process

Author: Pierre-François Calmon, Stephane Calvez, Chantal Fontaine, Olivier Gauthier-Lafaye, Alexandre Arnoult, Guilhem Almuneau, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), CNES R&T R-S13/LN-0001-025 / DA: Peigne de fréquences sur puce, Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Fabrication, Materials science, business.industry, Process (computing), Oxide, 02 engineering and technology, Atomic and Molecular Physics, and Optics, chemistry.chemical_compound, 020210 optoelectronics & photonics, Optics, Semiconductor, chemistry, Physical vapor deposition, 0202 electrical engineering, electronic engineering, information engineering, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, OCIS codes: (2307370) Waveguides, (1300130) Integrated optics, (1303130) Integrated optics materials, Planar process, Wafer, Photonics, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, business
Abstract: International audience; In this letter, we demonstrate that buried oxide-confined waveguides can be formed using a lateral oxidation process carried out through a discrete set of small-diameter via holes instead of the conventional scheme where the oxidation starts from the edges of etched mesas. The via-hole oxidation is shown to lead to straight waveguides with smooth oxide/semiconductor interfaces and whose propagation losses are similar to the one obtained using the standard process but with the advantage of maintaining a quasi-planar wafer surface. It thereby paves the way towards a simplification of the fabrication of III-V-semiconductor-oxide photonic devices.
Published: 2017

16. Un flacon bicolore énigmatique, d’époque islamique, au Musée universitaire de Louvain. Restauration et étude

Author: Chantal Fontaine-Hodiamont, Bernard GRATUZE, Université d'Orléans, SCD, IRAMAT - Centre Ernest Babelon (IRAMAT-CEB), Institut de Recherches sur les Archéomatériaux (IRAMAT), and Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM)
Subjects: Restauration, [SHS.ARCHEO] Humanities and Social Sciences/Archaeology and Prehistory, [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, [SHS.HIST] Humanities and Social Sciences/History, Flacon bicolore, Musée universitaire de Louvain, [SHS.HIST]Humanities and Social Sciences/History, Epoque islamique, ComputingMilieux_MISCELLANEOUS, Etude
Abstract: International audience
Published: 2017

17. Thermal annealing effects on optical and structural properties of GaBiAs epilayers: Origin of the thermal annealing-induced redshift in GaBiAs

Author: Omer Donmez, Ayse Erol, Chantal Fontaine, Hajer Makhloufi, Elif Akalin, Alexandre Arnoult, Kamuran Kara, Istanbul University, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: Materials science, Band gap, Alloy, Analytical chemistry, 02 engineering and technology, engineering.material, 01 natural sciences, Spectral line, [SPI.MAT]Engineering Sciences [physics]/Materials, symbols.namesake, 0103 physical sciences, Thermal, Materials Chemistry, Spectroscopy, 010302 applied physics, Condensed matter physics, Mechanical Engineering, Metals and Alloys, 021001 nanoscience & nanotechnology, Thermal conduction, Redshift, Mechanics of Materials, engineering, symbols, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, 0210 nano-technology, Raman spectroscopy
Abstract: International audience; We report on an investigation of optical and structural properties of as-grown and thermal annealed GaBixAs1−x (x = 0.012, 0.018 and 0.03) epilayers by photomodulated reflectance (PR) spectroscopy, atomic force microscopy (AFM) and micro-Raman spectroscopy. PR spectra are analyzed by third derivative functional form (TDFF) lineshape. Optical transition energies are calculated using strain-included valence band anticrossing (VBAC) model. According to the results, optical transitions are from conduction bandedge to heavy hole bandedge and to light hole bandedge, which are affected by compressive strain and effect of strain is clearly seen when Bi concentration exceeds 2%. We also determine the band-anticrossing interaction parameter CBiM as 1.33 eV. TDFF analysis of as-grown and thermal annealed samples reveal that thermal annealing causes an unexpectedly large redshift of ∼22 meV/Bi% in the bandgap that corresponds to the increase of Bi composition by ∼25% in the GaAs lattice. The origin of this redshift is analyzed by AFM and Raman spectroscopy. Surface morphology of the GaBiAs samples show that droplets appear on the GaBiAs surface and their sizes increase with increasing Bi concentration, but tend to decrease following thermal annealing process and some surface droplets leave pits in their locations. Raman spectroscopy and AFM results give hints of diffusion of some Bi atoms from surface into the epilayer that causes an increase in Bi concentration of the alloy. This increase explains the observed annealing-induced redshift of the bandgap in PR measurement.
Published: 2016

18. Links between bismuth incorporation and surface reconstruction during GaAsBi growth probed by in situ measurements

Author: Alexandre Arnoult, Clara Cornille, Quentin Gravelier, Chantal Fontaine, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: III-V semiconductors, Materials science, Analytical chemistry, General Physics and Astronomy, chemistry.chemical_element, in situ measurements, 02 engineering and technology, Epitaxy, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Bismuth, strain, Desorption, bismuth, 0103 physical sciences, 010302 applied physics, Surface stress, 021001 nanoscience & nanotechnology, chemistry, Electron diffraction, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Atomic ratio, 0210 nano-technology, Surface reconstruction, Molecular beam epitaxy
Abstract: Bismuth incorporation and surface reconstruction have been studied simultaneously during GaAsBi growth by molecular beam epitaxy by means of in situ wafer curvature monitoring and reflection high energy electron diffraction, respectively. Growth temperature and flux ratio have been varied successively. As/Ga atomic ratio close to unity has been applied for the study of the growth temperature effect. During the growth regime under the (1 × 3) reconstruction, Bi incorporation is found to be independent of the growth temperature, for temperatures where Bi desorption is insignificant. On the contrary, Bi incorporation becomes highly dependent on the growth temperature as soon as the (2 × 1) reconstruction regime is reached. Only for the lowest temperatures, the Bi incorporation reaches the same level during the (2 × 1) reconstruction than for the (1 × 3) reconstruction. When the As/Ga flux ratio is increased, the bismuth incorporation is observed to decrease for GaAsBi growth in the (2 × 1) reconstruction regime. Our results indicate that the (1 × 3) and (2 × 1) surface reconstructions are always successively observed and that an energy barrier has to overcome to transit from the (1 × 3) to the (2 × 1) reconstruction, with this mechanism being temperature dependent. Finally, a difference in surface stress with reconstruction has been identified.
Published: 2019

19. Record high-aspect-ratio GaAs nano-grating lines grown by Hydride Vapor Phase Epitaxy (HVPE)

Author: Dominique Castelluci, Mohammed R. Ramdani, Evelyne Gil, Yamina André, Agnès Trassoudaine, and Chantal Fontaine
Subjects: Supersaturation, Nanostructure, Chemistry, business.industry, Scattering, Mineralogy, Surface finish, Grating, Condensed Matter Physics, Epitaxy, Inorganic Chemistry, Materials Chemistry, Optoelectronics, Dry etching, business, Anisotropy
Abstract: Nanometric-width GaAs grating lines showing high aspect (height/width) ratio of up to 30, without roughness or shape deviation are reported. They were obtained by HVPE, capitalizing on the near-equilibrium nature of this epitaxial technique. HVPE rapid decomposition of GaCl growth precursors leads to immediate reactivity of the growth reaction to an increase or decrease of the supersaturation of the vapor phase. HVPE growth is also governed by surface kinetics: the morphologies are controlled by the intrinsic growth anisotropy of the crystals. By manipulating surface kinetics and exploiting the fast reactivity of the system, it is demonstrated that HVPE allows to benefit from an enhanced growth anisotropy favoring vertical growth of nanometer-scale grating lines. Unique high-aspect ratios are obtained in one-step short growth time (20 min), capitalizing upon the main advantage of the bottom-up approach: the structures are defined by their crystalline properties with no scattering defects as typically introduced by techniques involving dry etching. The role of surface kinetics and mass transport at the nanometer scale is discussed.
Published: 2013

20. Carrier dynamics in GaAsBi quantum wells

Author: Delphine Lagarde, S. Azaizia, Hélène Carrère, Chantal Fontaine, Alexandre Arnoult, Xavier Marie, Andrea Balocchi, Équipe Microondes et Opto-microondes pour Systèmes de Télécommunications (LAAS-MOST), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Équipe Photonique (LAAS-PHOTO), Prof. Shumin Wang, Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Dr. K. Makasheva, and Dr. C. Bonafos
Subjects: 010302 applied physics, Range (particle radiation), Photoluminescence, Materials science, Fabrication, business.industry, 02 engineering and technology, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Condensed Matter::Materials Science, Wavelength, Semiconductor, 0103 physical sciences, [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, Electronic band structure, business, Carrier dynamics, ComputingMilieux_MISCELLANEOUS, Quantum well
Abstract: Dilute bismide semiconductors are key materials for a wide range of applications. Indeed, the introduction of Bi in a GaAs-based matrix leads to a strong modification of the electronic band structure. This opens up the possibility of tuning GaAs-based alloys in a large energy range. We report here on the fabrication of GaAsBi quantum wells and investigate the carrier dynamics by means of time resolved photoluminescence. We show that good optical quality can be obtained at wavelengths close to the telecommunication windows, which confirms the high potential of dilute bismide alloys for optoelectronics.
Published: 2016

21. Modelling of interband transitions in GaAs tunnel diode

Author: Guilhem Almuneau, François Olivie, François Piquemal, Chantal Fontaine, Alexandre Arnoult, Alexandre Bounouh, Guy Lacoste, Kevin Louarn, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire National de Métrologie et d'Essais [Trappes] (LNE ), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Équipe MICrosystèmes d'Analyse (LAAS-MICA), Laboratoire commun de métrologie LNE-CNAM (LCM), Laboratoire National de Métrologie et d'Essais [Trappes] (LNE )-Conservatoire National des Arts et Métiers [CNAM] (CNAM), Laboratoire Capteurs et Architectures Electroniques (LCAE), Département Métrologie Instrumentation & Information (DM2I), Laboratoire d'Intégration des Systèmes et des Technologies (LIST), 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)-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)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, European Project: 609698,EC:FP7:PEOPLE,FP7-PEOPLE-2013-NIGHT,RENATECH(2013), European Project: JRP ENG51,SolCell, Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA))
Subjects: Materials science, multi-junction solar cells, 02 engineering and technology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, tunnel junction, Tunnel junction, Condensed Matter::Superconductivity, 0103 physical sciences, Materials Chemistry, Tunnel diode, Electrical and Electronic Engineering, Conduction band, Quantum tunnelling, 010302 applied physics, Coupling, Condensed matter physics, business.industry, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Flietner's relation, band-to-band tunneling, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Electronic, Optical and Magnetic Materials, Amplitude, Valence band, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, 0210 nano-technology, business, Current density
Abstract: International audience; In this paper, an improved model for non-local band-to-band tunneling carrier transport is presented and compared to experimental measurement from GaAs tunnel junctions devices. By carefully taking into account the coupling between the conduction band and the light holes valence band, the model is able to predict, with realistic material parameters, the amplitude of the current density throughout the whole tunneling regime. The model suggests that elastic band-to-band tunneling instead of trap-assisted-tunneling is the predominant mechanism in GaAs tunnel junctions, which is of great interest for better understanding and improving III–V multijunction solar cells.
Published: 2016

22. Jonctions tunnels à base d'hétérostructures à semiconducteurs III-V pour les cellules solaires multi-jonctions à haut rendement

Author: Kevin Louarn, Alexandre Bounouh, Chantal Fontaine, François Olivie, Guillaume Libaude, Alexandre Arnoult, François Piquemal, Delvallee, A., Guilhem Almuneau, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Laboratoire National de Métrologie et d'Essais [Trappes] (LNE ), Équipe MICrosystèmes d'Analyse (LAAS-MICA), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Laboratoire commun de métrologie LNE-CNAM (LCM), Laboratoire National de Métrologie et d'Essais [Trappes] (LNE )-Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, ComputingMilieux_MISCELLANEOUS, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract: National audience
Published: 2015

23. Technological Solutions for Embedded Oxide-based Confinement in New Photonic III-V Device Architectures

Author: Guilhem Almuneau, Stephane Calvez, Olivier Gauthier-Lafaye, Fares Chouchane, Chantal Fontaine, Youness Laaroussi, Gael Lafleur, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, business.industry, Oxide, Grating, Epitaxy, 7. Clean energy, Structuring, Vertical-cavity surface-emitting laser, Resonator, chemistry.chemical_compound, chemistry, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, Photonics, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, business, Refractive index, ComputingMilieux_MISCELLANEOUS
Abstract: New technological capabilities of the selective wet oxidation process of AlGaAs are presented, including an original approach based on epitaxial regrowth on partially oxidized layers. This opens the path to complex integrated 3D structuring for photonic devices, such as oxide-based high contrast grating VCSEL and non-linear optical resonators.
Published: 2015

24. A new approach of planar oxidation of buried Al x Ga 1– x As/GaAs epitaxial structures for optical and electrical confinement applications

Author: Guilhem Almuneau, Jean-Baptiste Doucet, Alexandre Arnoult, Chantal Fontaine, G. Lacoste, and F. Chouchane
Subjects: Materials science, business.industry, Oxide, Condensed Matter Physics, Epitaxy, chemistry.chemical_compound, Planar, Stack (abstract data type), chemistry, Optoelectronics, business, Ternary operation, Lithography, Layer (electronics), Electron-beam lithography
Abstract: We propose an original approach of lateral confinement through oxidation of buried AlGaAs layers and epitaxial regrowth. The buried AlGaAs layer is selectively oxidized from the surface thanks to an array of sub-micron holes defined by electron beam lithography and etched in the GaAs/AlGaAs epitaxial structure. Oxidation spreads laterally into the Al-rich ternary surrounding the holes until the adjacent oxide fronts coalesce. Finally, epitaxial regrowth is used to stack further epitaxial layers above the partially oxidized structure. This technology enables free engineering of localized buried oxide areas through standard lithography techniques, unlike the standard process of lateral oxidation on mesas with size of a few decamicrons for which the oxide aperture is circumcised by the initial mesa shape. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Published: 2011

25. Management of the electrical injection uniformity in broad-area top-emitting VCSELs

Author: Jean-Baptiste Doucet, Ludovic Salvagnac, Véronique Bardinal, M. Condé, E. Havard, Thierry Camps, Guilhem Almuneau, Sébastien Pinaud, and Chantal Fontaine
Subjects: Physics, Optics, business.industry, Optical physics, Nonlinear optics, Plasma, business, Layer (electronics), Atomic and Molecular Physics, and Optics, Power (physics)
Abstract: The electrical properties of broad-area 850 nm top emitting VCSELs have been investigated in order to improve carrier injection uniformity in their active zone. First, we have demonstrated using an electrical simulation tool that a multi-point localized injection design associated with a spreading layer at the top of the device (ITO) can lead to a significant improvement of carrier injection and on its spatial distribution. Secondly, the electrical contrast achievable by applying this method with localized etchings has been experimentally measured. Finally, stripe-shaped devices with output power up to 50 mW in a continuous-wave operation at room temperature have been demonstrated.
Published: 2010

26. Electromodulation spectroscopy of heavy-hole, light-hole, and spin-orbit transitions in GaAsBi layers at hydrostatic pressure

Author: Robert Kudrawiec, Marta Gladysiewicz, Chantal Fontaine, O. Ligor, Cosmin Romanitan, E.-M. Pavelescu, J. Kopaczek, F. Dybala, Alexandre Arnoult, Wroclaw University of Science and Technology, IMT Bucharest, IMT, Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Équipe Photonique (LAAS-PHOTO), Wroclaw University of Technology [Wroclaw], Service Techniques et Équipements Appliqués à la Microélectronique ( LAAS-TEAM ), Laboratoire d'analyse et d'architecture des systèmes [Toulouse] ( LAAS ), Institut National Polytechnique [Toulouse] ( INP ) -Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut National Polytechnique [Toulouse] ( INP ) -Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Centre National de la Recherche Scientifique ( CNRS ), Équipe Photonique ( LAAS-PHOTO ), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: Materials science, Physics and Astronomy (miscellaneous), [ SPI.MAT ] Engineering Sciences [physics]/Materials, Hydrostatic pressure, [ PHYS.COND.CM-MS ] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 02 engineering and technology, Substrate (electronics), 01 natural sciences, Molecular physics, Spectral line, [SPI.MAT]Engineering Sciences [physics]/Materials, Gallium arsenide, Condensed Matter::Materials Science, chemistry.chemical_compound, 0103 physical sciences, Electronic band structure, Spectroscopy, 010302 applied physics, 021001 nanoscience & nanotechnology, chemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Density functional theory, [ SPI.OPTI ] Engineering Sciences [physics]/Optics / Photonic, 0210 nano-technology, Molecular beam epitaxy
Abstract: International audience; GaAsBi layers of various Bi concentrations have been grown by molecular beam epitaxy on a GaAs substrate and studied by electromodulation spectroscopy (EM). Optical transitions related to heavy-hole (HH) and light-hole (LH) bands as well as the spin-orbit (SO) split-off band have been observed in EM spectra, and their energies have been found to be in very good agreement with theoretical predictions, which take into account the strain-related shifts obtained from the Bir-Pikus theory implemented to the electronic band structure of GaAsBi obtained after recent density functional theory (DFT) calculations for this alloy. The pressure coefficients for HH, LH, and SO transitions have been determined from photoreflectance measurements performed at various hydrostatic pressures and discussed.
Published: 2017

27. XPS study of the O2/SF6 microwave plasma oxidation of (001) GaAs surfaces

Author: O. Desplats, Luc Bideux, Chantal Fontaine, Guillaume Monier, Bernard Gruzza, Christine Robert-Goumet, Institut Pascal (IP), SIGMA Clermont (SIGMA Clermont)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire des sciences et matériaux pour l'électronique et d'automatique (LASMEA), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Plasma parameters, 020209 energy, Analytical chemistry, Oxide, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, Surfaces and Interfaces, General Chemistry, Plasma, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Oxygen, Ion source, Surfaces, Coatings and Films, chemistry.chemical_compound, chemistry, X-ray photoelectron spectroscopy, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0202 electrical engineering, electronic engineering, information engineering, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Gallium, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Microwave
Abstract: O2SF6 plasma effects on processed GaAs surfaces have been investigated. The influence of plasma parameters such as composition, power and exposure time has been studied. The microwave plasma treatment efficiency has been studied by surface depth profiling (cycles consisting of XPS measurements followed by a slight etching) coupled with an original modelling calculation. We have pointed out that SF6 addition in plasma increases the oxidative rule of oxygen by increasing the total oxide thickness and that the quantity of the different oxidative and passivating species does not limit the oxidative mechanism, in the O2:SF6 ratio range 80:20 to 40:60. The increase in the plasma power leads to a change in the composition of the outer region of the oxide layer with an increase in the gallium content on the surface, and to an increase in the total oxide layer. The exposure time to the plasma increases also these two phenomena.
Published: 2009

28. Dislocation Nucleation in Heteroepitaxial Semiconducting Films

Author: N. Burle, Chantal Fontaine, Bernard Pichaud, V.I. Vdovin, and Michael Texier
Subjects: Materials science, Condensed matter physics, business.industry, Relaxation (NMR), Nucleation, Condensed Matter Physics, Crystallographic defect, Atomic and Molecular Physics, and Optics, Condensed Matter::Materials Science, Crystallography, Semiconductor, General Materials Science, Dislocation, Anisotropy, business, Layer (electronics), Vicinal
Abstract: The nucleation of dislocation in semiconductors is still a matter of debate and especially in heteroepitaxial films. To understand this nucleation process the classical models of dislocation nucleation are presented and discussed. Two main points are then developed: emission of dislocations from surface steps and the role of point defects agglomeration on dislocation nucleation. Recent atomic simulation of half loops emission from surface steps and experimental evidences of anisotropic relaxation of GaInAs films deposited on vicinal (111) GaAs substrates strongly support surface steps as preferential sites for nucleation. In low temperature buffer layer structures (SiGe/Si) an original dislocation structure is observed which corresponds to the dislocation emission in different glide systems by a unique nucleation centre.
Published: 2009

29. Dislocation nucleation in heteroepitaxial semiconducting films

Author: V.I. Vdovin, Michael Texier, J. Thibault-Penisson, Marc Gailhanou, Claude Alfonso, N. Burle, Chantal Fontaine, and Bernard Pichaud
Subjects: Condensed matter physics, Chemistry, business.industry, Relaxation (NMR), Nucleation, Condensed Matter Physics, Crystallographic defect, Condensed Matter::Materials Science, Crystallography, Semiconductor, Dislocation, business, Anisotropy, Layer (electronics), Vicinal
Abstract: The nucleation of dislocation in semiconductors is still a matter of debate and especially in heteroepitaxial films. To understand this nucleation process the classical models of dislocation nucleation are presented and criticized. Two main points are then developed: emission of dislocations from surface steps and the role of point defects agglomeration on dislocation nucleation. Recent atomic simulation of half loops emission from surface steps and experimental evidences of anisotropic relaxation of GaInAs films deposited on vicinal (111) GaAs substrates strongly support surface steps as preferential sites for nucleation. In low temperature buffer layer structures (SiGe/Si) an original dislocation structure is observed which corresponds to the dislocation emission in different glide systems by a unique nucleation centre. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Published: 2009

30. Photoluminescence in n and p modulation-doped GaInNAs/GaAs quantum wells

Author: Markku Sopanen, Bulent Ulug, Outi Reentilä, M. Yilmaz, Y. Sun, Chantal Fontaine, Alexandre Arnoult, Naci Balkan, Marco Mattila, and A. Ulug
Subjects: Photoluminescence, Materials science, Condensed matter physics, business.industry, Band gap, Doping, General Engineering, Blueshift, Condensed Matter::Materials Science, Semiconductor, Condensed Matter::Superconductivity, Condensed Matter::Strongly Correlated Electrons, business, Quantum well, Non-radiative recombination, Extrinsic semiconductor
Abstract: Experimental results concerning the steady-state photoluminescence (PL) studies in n and p modulation doped and undoped GaInNAs/GaAs quantum wells are presented. The effects of modulation, type of doping and nitrogen concentration on the PL and the temperature dependence of the band gap, carrier localization and non-radiative recombination are investigated. Increasing the nitrogen composition decreases energy band gap as expected. The n-type modulation doping eliminates most of the defect-related effects and blue shifts the energy band gap. However, the p-type doping gives rise to additional features in the PL spectra and red shifts energy band gap further compared to the n-type-doped material.
Published: 2009

31. On the use of a O2:SF6 plasma treatment on GaAs processed surfaces for molecular beam epitaxial regrowth

Author: C. Armand, Luc Bideux, Guy Lacoste, Laurent Jalabert, Chantal Fontaine, P. Gallo, Alexandre Arnoult, O. Desplats, Jean-Baptiste Doucet, F. Voillot, and Guillaume Monier
Subjects: Auger electron spectroscopy, Materials science, Oxide, Analytical chemistry, General Physics and Astronomy, Surfaces and Interfaces, General Chemistry, Substrate (electronics), Condensed Matter Physics, Epitaxy, Ion source, Surfaces, Coatings and Films, Secondary ion mass spectrometry, chemistry.chemical_compound, chemistry, Molecular beam, Molecular beam epitaxy
Abstract: Preparation of processed GaAs surface cleaning in view of molecular beam epitaxy regrowth by means of a O 2 SF 6 microwave plasma has been investigated. Photoemission, Auger electron spectroscopy, atomic force microscopy and secondary ion mass spectrometry have been used for characterization. The O 2 SF 6 plasma treatment was found to be very efficient for decontaminating the GaAs surface and leads to the formation of an oxide layer that can be taken off by a thermal or low-temperature H-plasma-assisted deoxidation. The levels of oxygen and carbon contaminants at the regrowth interface were measured to be in the range of a standard homoepitaxial layer–epiready substrate interface. Fluorine was observed to be eliminated upon deoxidation while sulphur is present, particularly in the case of low temperature grown layers. This plasma treatment was found to be efficient for preparation of processed GaAs surfaces for molecular beam epitaxial regrowth.
Published: 2009

32. Structure-induced effects on the selective wet thermal oxidation of digital AlxGa1–xAs alloys

Author: Guilhem Almuneau, M. Condé, Isaac Suárez, Chantal Fontaine, and L. Bouscayrol
Subjects: Arrhenius equation, Thermal oxidation, X-ray absorption spectroscopy, Nanostructure, Fabrication, Materials science, Mechanical Engineering, Superlattice, Analytical chemistry, Condensed Matter Physics, Reaction rate, symbols.namesake, Mechanics of Materials, symbols, General Materials Science, Wet oxidation
Abstract: A thorough study of the selective wet oxidation in digital AlxGa1–xAs alloys is presented. We report experimental results and physical interpretation on the oxidation kinetics within those ranges of the AlGaAs composition (x = 0.95 to 1) and layer thickness (20 to 50 nm) of interest for oxide-aperture vertical-cavity surface-emitting laser (VCSEL) application. We demonstrate the high controllability of the oxidation reaction between different Al compositions; made different thanks to the use of digital alloys. Unlike standard alloys, we measured an invariability of the oxidation rates in the studied thickness range (20–50 nm), implying a better control of the fabrication process. The dependence of the reaction rate with the temperature is expressed as an Arrhenius law. Two activation energies (1.2 and 0.55 eV) have been derived for composition ranges of x = 0.95–0.98 and x = 0.99–1, respectively, revealing that two different mechanisms are involved depending on the Al content and the superlattice structure of the digitally-grown AlGaAs.
Published: 2008

33. High aspect ratio GaAs nanowires made by ICP-RIE etching using Cl2/N2 chemistry

Author: Laurent Jalabert, Pascal Dubreuil, Franck Carcenac, Hugues Granier, Ludovic Salvagnac, Chantal Fontaine, and Sébastien Pinaud
Subjects: Materials science, Plasma etching, business.industry, Nanowire, Analytical chemistry, Substrate (electronics), Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Etching (microfabrication), Miniaturization, Optoelectronics, Electrical and Electronic Engineering, Inductively coupled plasma, Reactive-ion etching, business, Electron-beam lithography
Abstract: We report an experimental study of GaAs etching by ICP-RIE based on Cl2:N2 chemistry. The influence of the RF source power, the chlorine dilution, the RF platen power, and the process pressure at several substrate temperatures are investigated. An optimized process is proposed to get routinely GaAs nanowires of 1µm high and about 30nm in diameter with a full top-down approach combining electron beam lithography and Ni lift-off steps.
Published: 2008

34. Photoluminescence studies in modulation doped GaInNAs/GaAs multiple quantum wells

Author: Ahmet Cicek, A. Ulug, Markku Sopanen, O. Reentilä, M. Yilmaz, Alexandre Arnoult, M. Mattila, Bulent Ulug, Naci Balkan, and Chantal Fontaine
Subjects: 010302 applied physics, Photoluminescence, Condensed matter physics, Chemistry, Band gap, Exciton, Doping, chemistry.chemical_element, 02 engineering and technology, Nitride, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Nitrogen, Modulation, 0103 physical sciences, 0210 nano-technology, Quantum well
Abstract: We report for the first time the temperature dependent PL spectra from GaInNAs/GaAs triple quantum wells, modulation doped with a 2-D carrier density of ∼3 × 1011 cm–2 per well. The measurements were carried out at temperatures between 10 and 300 K. The results are analyzed using a Gaussian fitting technique which indicates variable nitrogen composition and/or well-width fluctuations in the wells. One of the most striking features of the results is the lack of the S-Shape temperature dependence of the PL peak energy that is commonly observed in undoped dilute nitride quantum wells and is attributed to exciton de-trapping, which screens the true temperature dependence of the energy gap. Our results compare well with the predictions of the Varshni equation. The temperature dependence of the PL intensity is used to obtain the thermally activated behaviour of the non-radiative recombination processes that appear to dominate at higher temperatures. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Published: 2007

35. III-V based Heterojunction Tunnel for Multijunction Solar Cells

Author: Kevin Louarn, Alexandre Bounouh, Chantal Fontaine, François Olivie, Guillaume Libaude, François Piquemal, Delvallee, A., Guilhem Almuneau, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire National de Métrologie et d'Essais [Trappes] (LNE ), Équipe MICrosystèmes d'Analyse (LAAS-MICA), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Laboratoire commun de métrologie LNE-CNAM (LCM), Laboratoire National de Métrologie et d'Essais [Trappes] (LNE )-Conservatoire National des Arts et Métiers [CNAM] (CNAM), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), and HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)
Subjects: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, ComputingMilieux_MISCELLANEOUS, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract: National audience
Published: 2015

36. Optical properties of GaBiAs single quantum well structures grown by MBE

Author: M. C. Arikan, Ayse Erol, Chantal Fontaine, Omer Donmez, Hejer Makhloufi, Alexandre Arnoult, Istanbul University, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: Range (particle radiation), Materials science, Photoluminescence, Condensed matter physics, Atmospheric temperature range, Condensed Matter Physics, Spectral line, Electronic, Optical and Magnetic Materials, [SPI.MAT]Engineering Sciences [physics]/Materials, Amplitude, Materials Chemistry, Cluster (physics), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Electrical and Electronic Engineering, Molecular beam, Quantum well
Abstract: International audience; In this study, molecular beam epitaxial-grown GaAs/GaBiAs single quantum well systems with two different Bi contents were investigated. Spectral dependence of room temperature photomodulated reflectance (PR) and photoluminescence (PL) measurements in the temperature range of 35–300 K were employed. PR spectra indicate that increasing Bi concentration promotes a tendency to approach quantized higher energy levels in the heavy and light holes' bands due to the different effects of compressive strain, which depends on Bi concentrations. In addition, a defect level is identified at 0.71 eV at room temperature PR spectra and is attributed to a AsGa antisite defect in GaAs barrier layers caused by the low temperature growth process. From the analysis of the temperature dependence of emission energy and amplitude in the PL spectra, localized states are determined in the range of 8 to 45 meV and attributed to the different bonding configuration of Bi clusters. Low temperature PL results imply that Bi cluster states tend to move into the valance band when Bi content increases from 2.4 to 7.0% in the GaBiAs system.
Published: 2015

37. Evidence for subcomplexes in the Fanconi anemia pathway

Author: Jurgen Steltenpool, Chantal Fontaine, Hans Joenje, Annette L. Medhurst, Weidong Wang, Johan P. de Winter, Miriam Ferrer, Martin A. Rooimans, Rik J. Scheper, El Houari Laghmani, Amom Ruhikanta Meetei, and Jan de Groot
Subjects: Models, Molecular, congenital, hereditary, and neonatal diseases and abnormalities, Red Cells, Immunology, Fanconi Anemia Complementation Group L Protein, Mutation, Missense, In Vitro Techniques, Biology, Transfection, Biochemistry, Cell Line, FANCF, Fanconi anemia, FANCG, hemic and lymphatic diseases, FANCD2, medicine, Humans, FANCL, FANCM, Fanconi Anemia Complementation Group G Protein, Genetics, Fanconi Anemia Complementation Group A Protein, nutritional and metabolic diseases, Cell Biology, Hematology, medicine.disease, Fanconi Anemia Complementation Group Proteins, Recombinant Proteins, FANCA, FANCB, Cell biology, Fanconi Anemia, Multiprotein Complexes
Abstract: Fanconi anemia (FA) is a genomic instability disorder, clinically characterized by congenital abnormalities, progressive bone marrow failure, and predisposition to malignancy. Cells derived from patients with FA display a marked sensitivity to DNA cross-linking agents, such as mitomycin C (MMC). This observation has led to the hypothesis that the proteins defective in FA are involved in the sensing or repair of interstrand cross-link lesions of the DNA. A nuclear complex consisting of a majority of the FA proteins plays a crucial role in this process and is required for the monoubiquitination of a downstream target, FANCD2. Two new FA genes, FANCB and FANCL, have recently been identified, and their discovery has allowed a more detailed study into the molecular architecture of the FA pathway. We demonstrate a direct interaction between FANCB and FANCL and that a complex of these proteins binds FANCA. The interaction between FANCA and FANCL is dependent on FANCB, FANCG, and FANCM, but independent of FANCC, FANCE, and FANCF. These findings provide a framework for the protein interactions that occur “upstream” in the FA pathway and suggest that besides the FA core complex different subcomplexes exist that may have specific functions other than the monoubiquitination of FANCD2.
Published: 2006

38. Lateral Waveguiding Properties of VCSELs for Integrated Optical Monitoring

Author: C. Amat, Chantal Fontaine, Guilhem Almuneau, Véronique Bardinal, Emmanuelle Daran, Charlotte Bringer, Thierry Camps, and M. Suleiman
Subjects: Materials science, business.industry, Physics::Optics, Optical power, Laser, Waveguide (optics), Signal, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, law.invention, Semiconductor laser theory, Vertical-cavity surface-emitting laser, Optics, Transmission (telecommunications), law, Optoelectronics, Spontaneous emission, Electrical and Electronic Engineering, business
Abstract: We have investigated experimentally the optical behaviour of a Vertical-Cavity Surface-Emitting Lasers (VCSEL) when it is used as a lateral waveguide. This provides a better understanding of the mechanisms involved in VCSEL optical power monitoring by integrated lateral detection. The lateral optical spectra as well as the waveguide transmission spectrum have been measured. Their analysis and comparison demonstrate that the lateral signal is mostly coming from the spontaneous emission escaping laterally from the VCSEL and that light is filtered during the propagation and detection processes. This allows us to explain previous results obtained in two different configurations of lateral detection. These results are useful to optimize the lateral detection performances for concrete applications in monitoring or telemetry systems.
Published: 2006

39. Anisotropic electrongfactor as a probe of the electronic structure ofGaBixAs1−x/GaAsepilayers

Author: Ayse Erol, Christopher A. Broderick, Xavier Marie, Eoin P. O'Reilly, Alexandre Arnoult, Omer Donmez, Muhammad Usman, Hélène Carrère, Simone Mazzucato, Thierry Amand, Chantal Fontaine, and Hejer Makhloufi
Subjects: Condensed Matter::Materials Science, Materials science, Valence (chemistry), Quantum beats, Photoluminescence, Condensed matter physics, Landé g-factor, Electron, Electronic structure, Condensed Matter Physics, Anisotropy, Spectroscopy, Electronic, Optical and Magnetic Materials
Abstract: The electron Lande g factor (g∗) is investigated both experimentally and theoretically in a series of GaBixAs1−x/GaAs strained epitaxial layers, for bismuth compositions up to x=3.8%. We measure g∗ via time-resolved photoluminescence spectroscopy, which we use to analyze the spin quantum beats in the polarization of the photoluminescence in the presence of an externally applied magnetic field. The experimental measurements are compared directly to atomistic tight-binding calculations on large supercells, which allows us to explicitly account for alloy disorder effects. We demonstrate that the magnitude of g∗ increases strongly with increasing Bi composition x and, based on the agreement between the theoretical calculations and experimental measurements, elucidate the underlying causes of the observed variation of g∗. By performing measurements in which the orientation of the applied magnetic field is changed, we further demonstrate that g∗ is strongly anisotropic. We quantify the observed variation of g∗ with x, and its anisotropy, in terms of a combination of epitaxial strain and Bi-induced hybridization of valence states due to alloy disorder, which strongly perturbs the electronic structure.
Published: 2014

40. Quantum wells of dilute nitrides grown on GaAs by molecular beam epitaxy

Author: Véronique Bardinal, Alexandre Arnoult, F Gonzalez-Posada, Chantal Fontaine, and S. Blanc
Subjects: Materials science, Photoluminescence, business.industry, chemistry.chemical_element, Substrate (electronics), Nitride, Condensed Matter Physics, Nitrogen, Atomic and Molecular Physics, and Optics, Optical quality, Electronic, Optical and Magnetic Materials, Secondary ion mass spectrometry, chemistry, Optoelectronics, business, Quantum well, Molecular beam epitaxy
Abstract: Dilute nitrides are promising alloys in view of extending potential micro- and opto-electronics applications of GaAs technology. Orientation effects on nitrogen incorporation in GaAs have been scarcely addressed. Here, GaAsN on (100) and on As(B)- and Ga(A)-rich (111) substrates was grown by molecular beam epitaxy at different substrate temperatures. Nitrogen content measured by secondary ion mass spectrometry as a function of the growth temperature highlights the influence of orientation on nitrogen incorporation. Furthermore, thermal annealing is shown to improve the optical quality of GaAsN quantum wells whatever their substrate orientations.
Published: 2004

41. Characterization by X-ray diffraction and electron microscopy of GaInAs and GaAsN single layers and quantum wells grown on GaAs

Author: Chantal Fontaine, Claude Alfonso, H Varlet, M Laügt, N Burle, Alexandre Arnoult, and C. Curtil
Subjects: Diffraction, Thin layers, Materials science, Condensed matter physics, business.industry, Relaxation (NMR), Stacking, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Reciprocal lattice, Optics, X-ray crystallography, Nanometre, business, Quantum well
Abstract: Experiments were performed on thick GaInAs and GaAsN layers and on GaInAs quantum wells grown on (1 1 1) B and (0 0 1) GaAs substrates. The aim of this work is to develop an experimental procedure in order to evaluate the chemical compositions and relaxation state of the samples at global as well as nanometre scale. Chemical analyses (EDS, RBS, etc.), X-ray diffraction (reciprocal space map, sin2ψ, etc.) and XTEM were carried out. The validity of the sin2ψ method on the above mentioned thin layers has been tested. Good accuracy is obtained for In and N composition but more work has to be done in order to optimize the determination of the relaxation state. Coupling TEM observations to these calculations gives valuable information on the relaxation mechanisms (misfit dislocations, stacking faults, microtwins, etc.).
Published: 2004

42. Comparative I(V) study of pure Schottky contacts used in spin-LEDs

Author: R. Mamy, S. Couderc, Chantal Fontaine, Alexandre Arnoult, and Jean-François Bobo
Subjects: Materials science, Condensed Matter::Other, business.industry, Schottky barrier, Schottky diode, Heterojunction, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Condensed Matter Physics, Metal–semiconductor junction, Electronic, Optical and Magnetic Materials, Condensed Matter::Materials Science, Semiconductor, Depletion region, Materials Chemistry, Optoelectronics, Electrical and Electronic Engineering, business, Quantum tunnelling, Quantum well
Abstract: In this paper, we present the analysis of the results of I(V) characteristics of n-GaAs/Co Schottky structures and of spin-LED structures of the type [p-GaAs/p-AlGaAs/AlGaAs/GaAs/AlGaAs/n-AlGaAs]/Co where the semiconductor heterostructure acts as a quantum well LED. We have focused this study on tunneling through the space charge layer at the metal–semiconductor interface. We report strong differences for the I(V) characteristics of the two structures which can have important implications in the understanding of the exact mechanism of spin injection between a metal and a semiconductor.
Published: 2004

43. Spin injection probed by combined optical and electrical techniques in spin‐LED

Author: Chantal Fontaine, Pierre Renucci, Xavier Marie, Alexandre Arnoult, Hélène Carrère, M. Sénès, J. F. Bobo, B. L. Liu, Thierry Amand, and P. H. Binh
Subjects: Semiconductor, Photoluminescence, Condensed matter physics, Ferromagnetism, Chemistry, business.industry, Schottky barrier, Relaxation (NMR), Spin (physics), business, Circular polarization, Molecular beam epitaxy
Abstract: Spin-LEDs with a tunnel barrier made of a ferromagnetic metal (Co)/semiconductor (AlGaAs) Schottky junction were grown by combined molecular beam epitaxy and sputtering, and characterized. Under a longitudinal magnetic field of B = 0.8 T, we measured a circular polarization degree of the electro-luminescence (EL) of ∼4%. Using the electron spin relaxation and recombination times measured by time-resolved photoluminescence (TRPL), the yield of spin injection through Schottky contact of the spin-LED has been determined. We find η ∼ 30%. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Published: 2004

44. Interest of the orientation for GaAsN and GaInAsN/GaAs quantum wells grown by molecular beam epitaxy

Author: H. Carrère, Chantal Fontaine, S. Blanc, and Alexandre Arnoult
Subjects: Materials science, Photoluminescence, business.industry, Analytical chemistry, Substrate (electronics), Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Secondary ion mass spectrometry, Materials Chemistry, Optoelectronics, Growth rate, Electrical and Electronic Engineering, Spectroscopy, business, Luminescence, Quantum well, Molecular beam epitaxy
Abstract: GaAsN and GaInAsN have been grown on As(B)- and Ga(A)-rich {1 1 1} substrates by molecular beam epitaxy using a N plasma cell. Secondary ion mass spectrometry has been used to characterize N incorporation and photoluminescence spectroscopy to study the optical properties of GaAsN– and GaInAsN–GaAs wells. Difference in N incorporation has been found to be dependent on the substrate orientation: (111)A>(100)>(111)B. As for (1 0 0), the N content in A- and B-(1 1 1) GaAsN increases while the growth rate decreases. Optical properties of (1 1 1)A and (1 1 1)B oriented quantum wells (QWs) are very sensitive to growth conditions, whose optimum is drastically different from those of (1 0 0) and from each other. The better orientation appears to be the Ga-rich one, which allows for good luminescence properties to be obtained for GaAsN as well as for GaInAsN/GaAs wells. The strained (1 1 1)B QWs exhibit peculiar properties that can be assigned to the presence of defects originating from N incorporation.
Published: 2003

45. TEM evaluation of epitaxial strain in III–V semi-conductors: evidence of coherent and incoherent stress relaxation

Author: Chantal Fontaine, Stéphanie Blanc, André Rocher, and Anne Ponchet
Subjects: Materials science, Condensed matter physics, business.industry, General Physics and Astronomy, chemistry.chemical_element, Surfaces and Interfaces, General Chemistry, Substrate (electronics), Condensed Matter Physics, Epitaxy, Surfaces, Coatings and Films, Stress (mechanics), Crystallography, Semiconductor, chemistry, Stress relaxation, Relaxation (physics), Dislocation, business, Indium
Abstract: TEM studies have been performed in order to evaluate the amplitude and the uniformity of the strain field of epitaxial layers. Using adequate two-beam conditions, moire patterns allow us to measure independently the misfit strain components parallel and normal to the interface. The GaSb/(0 0 1)GaAs system has been studied by this technique. The measured spacings of moire fringes correspond well with the values calculated with the bulk parameters, thus indicating a complete relaxation. The mismatch accommodation is obtained by the direct creation of a Lomer dislocation network. In Ga 0.8 In 0.2 As/(0 0 1)GaAs system, the 10 nm thick epilayers do not give any contrast related to either organised misfit dislocations or strained layers. These observations show that the real strained state of the epitaxial layer is different from that predicted by the elastic theory. In fact the misfit stress, induced by a few percent of In, is high enough to perturb the ideal 2D growth: an indium segregation creates a transient composition with a random distribution of group III elements. This chemical behaviour induces a transition zone, between the substrate and the uniform epilayer, which contributes to the strain relaxation.
Published: 2002

46. Local stress-induced effects on AlGaAs/AlOx oxidation front shape

Author: Guilhem Almuneau, Fares Chouchane, Guy Lacoste, Alexandre Arnoult, Chantal Fontaine, Nikolay Cherkashin, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, Aluminium oxides, [PHYS]Physics [physics], Materials science, Physics and Astronomy (miscellaneous), Strain (chemistry), Absorption spectroscopy, Oxide, Analytical chemistry, 02 engineering and technology, Electron, 021001 nanoscience & nanotechnology, 01 natural sciences, Electron holography, Gallium arsenide, chemistry.chemical_compound, chemistry, Residual stress, 0103 physical sciences, Composite material, 0210 nano-technology
Abstract: cited By 4; International audience; The lateral oxidation of thick AlGaAs layers (>500 nm) is studied. An uncommon shape of the oxide tip is evidenced and attributed to the embedded stress distribution, inherent to the oxidation reaction. Experimental and numerical studies of the internal strain in oxidized AlxGa1−xAs/GaAs structures were carried out by dark-field electron holography and finite element methods. A mapping of the strain distribution around the AlGaAs/oxide interface demonstrates the main role of internal stress on the shaping of the oxide front. These results demonstrate the high relevance of strain in oxide-confined III-V devices, in particular, with over-500-nm thick AlOx confinement layers.
Published: 2014

47. Molecular beam epitaxy and properties of GaAsBi/GaAs quantum wells grown by molecular beam epitaxy: effect of thermal annealing

Author: Hélène Carrère, Alexandre Arnoult, Xavier Marie, Teresa Hungria, Guy Lacoste, Poonyasiri Boonpeng, Julien Nicolaï, Simone Mazzucato, Hajer Makhloufi, Chantal Fontaine, Anne Ponchet, Christophe Gatel, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Institut National des Sciences Appliquées (INSA), Surfaces, Interfaces et Nano-Objets (CEMES-SINanO), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), ANR-11-BS10-0017,NAIADE,Nanocaractérisation et modélisation d'Antimoniures d'éléments III : Interfaces et Analyse des Déformations d'Epitaxie(2011), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)
Subjects: Materials science, Photoluminescence, Annealing (metallurgy), chemistry.chemical_element, Nanochemistry, Nanotechnology, Bismuth, Condensed Matter::Materials Science, Materials Science(all), General Materials Science, Quantum well, [PHYS]Physics [physics], Nano Express, business.industry, Condensed Matter Physics, Heteroepitaxy, X-ray diffraction, Secondary ion mass spectrometry, chemistry, Transmission electron microscopy, Optoelectronics, business, Dilute bismides, Molecular beam epitaxy
Abstract: We have grown GaAsBi quantum wells by molecular beam epitaxy. We have studied the properties of a 7% Bi GaAsBi quantum well and their variation with thermal annealing. High-resolution X-ray diffraction, secondary ion mass spectrometry, and transmission electron microscopy have been employed to get some insight into its structural properties. Stationary and time-resolved photoluminescence shows that the quantum well emission, peaking at 1.23 μm at room temperature, can be improved by a rapid annealing at 650°C, while the use of a higher annealing temperature leads to emission degradation and blue-shifting due to the activation of non-radiative centers and bismuth diffusion from the quantum well.
Published: 2014

48. Planar technological solutions for emmbedded oxide-based confinement for new VCSELs architectures

Author: Guilhem Almuneau, Fares Chouchane, Stéphane Calvez, Chantal Fontaine, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, ComputingMilieux_MISCELLANEOUS, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract: International audience
Published: 2014

49. Photoluminescence from InGaAs/GaAs quantum well regrown on a buried patterned oxidized AlAs layer

Author: Guilhem Almuneau, Hajer Makhloufi, Chantal Fontaine, Stephane Calvez, Fares Chouchane, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: Photoluminescence, Materials science, Physics and Astronomy (miscellaneous), business.industry, Epitaxy, Laser, 7. Clean energy, Gallium arsenide, law.invention, [SPI.MAT]Engineering Sciences [physics]/Materials, chemistry.chemical_compound, Planar, chemistry, law, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, Photonics, business, Layer (electronics), Quantum well
Abstract: International audience; We present a quasi-planar technological approach for forming a flexible and versatile confinement scheme based on oxidation of AlGaAs buried layers combined to an epitaxial regrowth. This method improves the electrical and optical confinements compared to the lateral oxidation since it allows to define confinement areas from a planar surface. This technique is suitable for the realization of advanced integrated photonic components arrays with close device-to-device spacing such as two-dimensional arrays of vertical-cavity surface-emitting lasers. Our results prove that the oxidation and epitaxial regrowth can be sequenced in a process flow, leading to viable confinement while preserving good radiative properties.
Published: 2014

50. Non-stoichiometry in (001) low temperature GaAs by Raman spectroscopy

Author: R Bisaro, M. Toufella, E. Bedel, Robert Carles, Gérard Benassayag, R Sirvin, Pascal Puech, M Stellmacher, Chantal Fontaine, A. Claverie, and J Nagle
Subjects: Phonon, Chemistry, Scattering, Screening effect, Analytical chemistry, Condensed Matter Physics, Molecular physics, Condensed Matter::Materials Science, symbols.namesake, Thermal conductivity, symbols, General Materials Science, Raman spectroscopy, Raman scattering, Stoichiometry, Solid solution
Abstract: Using the optical phonons as an internal probe, the change in the dielectric permittivity has been analysed by Raman scattering in GaAs grown by MBE at low temperature (LT-GaAs). The screening effect is discussed in terms of a solid solution whereas the strain one is treated in the perfect adhesion hypothesis. Experimentally, the strain and the screening effects have been discriminated by using various scattering geometries. As the LT-layers with large non-stoichiometry have a poor thermal conductivity, it is shown that local heating considerably affects the experimental data. This can be avoided by surface convective exchange then leading to perfect agreement between the recorded phonon frequency shift and the expected ones. As a consequence, this sustains a new method for a quantitative determination of the As excess in LT-layers.
Published: 2000

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