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17 results on '"Philippe Schieffer"'

1. Simple renormalization schemes for multiple scattering series expansions

Author

Aika Takatsu, Sylvain Tricot, Philippe Schieffer, Kevin Dunseath, Mariko Terao-Dunseath, Keisuke Hatada, Didier Sébilleau, University of Toyama, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Grant No. 18K05027, Japan Society for the Promotion of Science, and Grant No. JPMJCR1861, Core Research for Evolutional Science and Technology

Subjects
[PHYS]Physics [physics], [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], General Physics and Astronomy, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Quantum dynamics, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Computer Science::Databases, Spectroscopy
Abstract

International audience; A number of renormalization schemes for improving the convergence of multiple scattering series expansions are investigated. Numerical tests on a small Cu(111) cluster demonstrate their effectiveness, for example increasing the rate of convergence by up to a factor 2 or by transforming a divergent series into a convergent one. These techniques can greatly facilitate multiple scattering calculations, especially for spectroscopies such as photoelectron diffraction, Auger electron diffraction, low energy electron diffraction , where an electron propagates with a kinetic energy of hundreds of eV in a cluster of hundreds of atoms.

Published
2022
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2. Optical and structural characterization of thin MoS2 layers on SiO2/Si substrates, towards the development of MoS2/Si heterojunction photovoltaics

Author

Laurent Pedesseau, Mircea Modreanu, Philippe Schieffer, Antoine Létoublon, Jacky Even, Bruno Lépine, Pascal Turban, Alain Moréac, Olivier Durand, Bienlo Zerbo, Alain Rolland, Ian M. Povey, Institut des Fonctions Optiques pour les Technologies de l'informatiON (Institut FOTON), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS), University College Cork (UCC), Institut de Physique de Rennes (IPR), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], Materials science, Silicon, Band gap, business.industry, chemistry.chemical_element, Heterojunction, Characterization (materials science), law.invention, chemistry, Photovoltaics, law, Solar cell, Optoelectronics, Crystallite, business, Photonic crystal
Abstract

International audience; In this paper, we present the first steps of a process toward the development of MoS2/Si heterojunctions photovoltaics, using 2D 2H-MoS2, whose natural abundance and tunable bandgap make it suitable for such application. A focus is made here on the optimization of the MoS2 material and its deposition process, through preliminary optical and structural characterizations of thin 2H-MoS2 layers deposited on 80nm SiO2 on top of Si (001) substrates. Our investigations revealed oxidation of the MoS2 layers, and limited longitudinal crystallite size, which may strongly affect the band lineup between MoS2 and Si, and thus, the performance of the solar cell.

Published
2021
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3. Epitaxial III–V/Si Vertical Heterostructures with Hybrid 2D‐Semimetal/Semiconductor Ambipolar and Photoactive Properties

Author

Rozenn Bernard, Mekan Piriyev, Gabriel Loget, Nicolas Bertru, Jacky Even, Philippe Schieffer, Lipin Chen, Christophe Levallois, Charles Cornet, Laurent Pedesseau, Imen Jadli, Sylvain Tricot, Bruno Fabre, Pascal Turban, Julie Le Pouliquen, Alexandre Beck, T. Rohel, Yoan Léger, Institut des Fonctions Optiques pour les Technologies de l'informatiON (Institut FOTON), École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique de Rennes (IPR), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), China Scholarship Council. Grant Number: 2017–6254, HPC resources of TGCC/CINES/IDRIS. Grant Numbers: 2020-A0080911434, 2021-A0100911434, Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)

Subjects
energy harvesting, 2D topological semimetal, Materials science, photo‐electro‐chemistry, Science, General Chemical Engineering, photonics, General Physics and Astronomy, Medicine (miscellaneous), hybrid heterostructures, 02 engineering and technology, 7. Clean energy, 01 natural sciences, Biochemistry, Genetics and Molecular Biology (miscellaneous), photo-electro-chemistry, 0103 physical sciences, General Materials Science, 010306 general physics, Research Articles, ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], III–V/Si, Ambipolar diffusion, business.industry, General Engineering, Heterojunction, [CHIM.CATA]Chemical Sciences/Catalysis, 021001 nanoscience & nanotechnology, Semimetal, Semiconductor, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, ambipolar properties, Charge carrier, Photonics, 0210 nano-technology, business, Hybrid material, Science, technology and society, III-V/Si, Research Article
Abstract

Hybrid materials taking advantage of the different physical properties of materials are highly attractive for numerous applications in today's science and technology. Here, it is demonstrated that epitaxial bi‐domain III–V/Si are hybrid structures, composed of bulk photo‐active semiconductors with 2D topological semi‐metallic vertical inclusions, endowed with ambipolar properties. By combining structural, transport, and photoelectrochemical characterizations with first‐principle calculations, it is shown that the bi‐domain III–V/Si materials are able within the same layer to absorb light efficiently, separate laterally the photo‐generated carriers, transfer them to semimetal singularities, and ease extraction of both electrons and holes vertically, leading to efficient carrier collection. Besides, the original topological properties of the 2D semi‐metallic inclusions are also discussed. This comb‐like heterostructure not only merges the superior optical properties of semiconductors with good transport properties of metallic materials, but also combines the high efficiency and tunability afforded by III–V inorganic bulk materials with the flexible management of nano‐scale charge carriers usually offered by blends of organic materials. Physical properties of these novel hybrid heterostructures can be of great interest for energy harvesting, photonic, electronic or computing devices., Here, it is demonstrated that epitaxial bi‐domain III–V/Si are hybrid structures, composed of bulk photo‐active semiconductors with 2D topological semi metallic vertical inclusions, endowed with ambipolar properties. Operating III–V/Si photoelectrodes confirm that this hybrid material can by itself photogenerate and laterally separate carriers, which are efficiently extracted afterward from the photoelectric device.

Published
2021
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4. Evidence of Pure Spin-Current Generated by Spin Pumping in Interface-Localized States in Hybrid Metal–Silicon–Metal Vertical Structures

Author

Jian Yin Qin, Xiufeng Han, Jean-Georges Mussot, Xavier Devaux, Henri Jaffrès, Piotr Łaczkowski, Sébastien Petit-Watelot, Zhi Liu, Stéphane Mangin, Yuan Lu, Huong Dang, Bu Wen Cheng, Abdelmadjid Anane, Juan-Carlos Rojas-Sánchez, J.-M. George, Jean-Christophe Le Breton, Abdelhak Djeffal, S. Suire, Carolina Cerqueira, Philippe Schieffer, Mathieu Stoffel, Michel Hehn, Sylvie Migot, Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), THALES [France]-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Solides Irradiés (LSI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), University of Chinese Academy of Sciences [Beijing] (UCAS), Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), This work is supported by the joint French National Research Agency (ANR)-National Natural Science Foundation of China (NNSFC) ENSEMBLE project (grant nos. ANR-14-CE26-0028-01 and NNSFC 61411136001), Chinese-French International Key Program, National Natural Science Foundation of China (NSFC grant no. 51620105004) and by the French PIA project 'Lorraine Université d’Excellence' (grant no. ANR-15-IDEX-04-LUE). C.C. acknowledges the support from CNPq, National Council for Scientific and Technological Development-Brazil. A.D. acknowledges PhD funding from Region Lorraine., IMPACT N4S, ANR-15-IDEX-0004,LUE,Isite LUE(2015), THALES-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Silicon, Population, chemistry.chemical_element, FOS: Physical sciences, wafer bonding, Bioengineering, 02 engineering and technology, Condensed Matter::Materials Science, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), [CHIM]Chemical Sciences, General Materials Science, inverse spin Hall effect, Spin (physics), education, [PHYS]Physics [physics], Spin pumping, education.field_of_study, Condensed Matter - Materials Science, spin current, Condensed matter physics, Condensed Matter - Mesoscale and Nanoscale Physics, Mechanical Engineering, Materials Science (cond-mat.mtrl-sci), General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, localized electronic states, Ferromagnetic resonance, Ferromagnetism, chemistry, Spin Hall effect, Spin diffusion, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology
Abstract

International audience; Due to the difficulty of growing high-quality semiconductors on ferromagnetic metals, the study of spin diffusion transport in Si was limited to lateral geometry devices. In this work, by using an ultrahigh-vacuum wafer-bonding technique, we have successfully fabricated metal–semiconductor–metal CoFeB/MgO/Si/Pt vertical structures. We hereby demonstrate pure spin-current injection and transport in the perpendicular current flow geometry over a distance larger than 2 μm in n-type Si at room temperature. In those experiments, a pure propagating spin current is generated via ferromagnetic resonance spin pumping and converted into a measurable voltage by using the inverse spin Hall effect occurring in the top Pt layer. A systematic study varying both Si and MgO thicknesses reveals the important role played by the localized states at the MgO–Si interface for the spin-current generation. Proximity effects involving indirect exchange interactions between the ferromagnet and the MgO–Si interface states appears to be a prerequisite to establishing the necessary out-of-equilibrium spin population in Si under the spin-pumping action.

Published
2019
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5. Reduction of Schottky Barrier Height at Graphene/Germanium Interface with Surface Passivation

Author

Philippe Schieffer, Gabriel Delhaye, Sylvain Tricot, Bruno Lépine, Pascal Turban, Alain Moréac, Jules Courtin, Jean-Christophe Le Breton, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), ANR-18-CE24-0017-01, Agence Nationale de la Recherche, ANR-18-CE24-0017,FEOrgSpin,Contrôle ferroélectrique de la spinterface organique/ferromagnétique(2018), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Passivation, Schottky barrier, chemistry.chemical_element, Germanium, 02 engineering and technology, Substrate (electronics), 01 natural sciences, lcsh:Technology, law.invention, lcsh:Chemistry, symbols.namesake, law, 0103 physical sciences, General Materials Science, Instrumentation, lcsh:QH301-705.5, surface passivation, 010302 applied physics, Fluid Flow and Transfer Processes, [PHYS]Physics [physics], Condensed matter physics, business.industry, Graphene, lcsh:T, Process Chemistry and Technology, graphene, General Engineering, Schottky diode, Schottky, 021001 nanoscience & nanotechnology, lcsh:QC1-999, Computer Science Applications, [SPI.TRON]Engineering Sciences [physics]/Electronics, germanium, Semiconductor, chemistry, lcsh:Biology (General), lcsh:QD1-999, lcsh:TA1-2040, symbols, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], van der Waals force, 0210 nano-technology, business, lcsh:Engineering (General). Civil engineering (General), lcsh:Physics, photoemission
Abstract

International audience; Fermi level pinning at metal/semiconductor interfaces forbids a total control over the Schottky barrier height. 2D materials may be an interesting route to circumvent this problem. As they weakly interact with their substrate through Van der Waals forces, deposition of 2D materials avoids the formation of the large density of state at the semiconductor interface often responsible for Fermi level pinning. Here, we demonstrate the possibility to alleviate Fermi-level pinning and reduce the Schottky barrier height by the association of surface passivation of germanium with the deposition of 2D graphene

Published
2019
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6. Band Alignments in Fe/Graphene/Si(001) Junctions Studied by X-ray Photoemission Spectroscopy

Author

Bruno Lépine, Philippe Schieffer, Gabriel Delhaye, Sylvain Tricot, J. C. Le Breton, Pascal Turban, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), ANR-14-CE26-0028,ENSEMBLE,Transport du spin des électrons et communication avec le spin nucléaire dans des structures verticales métal-SiGe-métal fabriqué par collage moléculaire(2014), ANR-14-0028-01, NSFC, National Natural Science Foundation of China, Le Breton, Jean-Christophe, Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and Appel à projets générique - Transport du spin des électrons et communication avec le spin nucléaire dans des structures verticales métal-SiGe-métal fabriqué par collage moléculaire - - ENSEMBLE2014 - ANR-14-CE26-0028 - Appel à projets générique - VALID

Subjects
Silicon, Silicides, Physics and Astronomy (miscellaneous), Schottky barrier, Iron, Nanotechnology, 02 engineering and technology, 01 natural sciences, law.invention, Schottky barrier heights, Passivation, Hydrogen passivation, law, Semiconductor devices, 0103 physical sciences, Semiconductor doping, 010306 general physics, Doping concentration, ComputingMilieux_MISCELLANEOUS, Graphene oxide paper, Elevated temperature, X ray photoemission spectroscopy, [PHYS]Physics [physics], Substrates, Graphene, business.industry, Doping, Magnetic dead layers, Heterojunction, Interface states, 021001 nanoscience & nanotechnology, Semimetal, [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Photoelectron spectroscopy, Semiconductor, Semiconducting silicon, Interface chemistry, Heterojunctions, Magnetoelectronics, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, Schottky barrier diodes, 0210 nano-technology, business, Spintronic device, Graphene nanoribbons
Abstract

International audience; The control of tunnel contact resistance is of primary importance for semiconductor-based spintronic devices. This control is hardly achieved with conventional oxide-based tunnel barriers due to deposition-induced interface states. Manipulation of single 2D atomic crystals (such as graphene sheets) weakly interacting with their substrate might represent an alternative and efficient way to design new heterostructures for a variety of different purposes including spin injection into semiconductors. In the present paper, we study by x-ray photoemission spectroscopy the band alignments and interface chemistry of iron-graphene-hydrogenated passivated silicon (001) surfaces for a low and a high n-doping concentration. We find that the hydrogen passivation of the Si(001) surface remains efficient even with a graphene sheet on the Si(001) surface. For both doping concentrations, the semiconductor is close to flat-band conditions which indicates that the Fermi level is unpinned on the semiconductor side of the Graphene/Si(001):H interface. When iron is deposited on the graphene/Si(001):H structures, the Schottky barrier height remains mainly unaffected by the metallic overlayer with a very low barrier height for electrons, a sought-after property in semiconductor based spintronic devices. Finally, we demonstrate that the graphene layer intercalated between the metal and semiconductor also serves as a protection against iron-silicide formation even at elevated temperatures preventing from the formation of a Si-based magnetic dead layer. © 2016 Author(s).

Published
2017
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7. Effective Metal Top Contact on the Organic Layer via Buffer-Layer-Assisted Growth: A Multiscale Characterization of Au/Hexadecanethiol/n-GaAs(100) Junctions

Author

Arnaud Le Pottier, Francine Solal, Sylvain Tricot, Soraya Ababou-Girard, Pascal Turban, Alexandra Junay, Sophie Guézo, Philippe Schieffer, José Avila, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), FEDER, Federación Española de Enfermedades Raras, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Multiscale characterizations, Materials science, Ballistic electron emission microscopy, Transport measurements, Nanotechnology, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Electron transport properties, Organic monolayers, Metal, Electron emission, Hot-electron transport, Monolayer, Buffer layers, Physical and Theoretical Chemistry, Nanoscopic scale, Spatial uniformity, Buffer-layer-assisted growth, Monolayers, [PHYS]Physics [physics], business.industry, Monolayer coverage, Molecular electronics, Heterojunction, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Characterization (materials science), General Energy, Metals, visual_art, visual_art.visual_art_medium, Optoelectronics, Gold, 0210 nano-technology, business, Layer (electronics)
Abstract

International audience; In the field of organic and molecular electronics at monolayer coverage, the need for abrupt and well-controlled top metal contacts is a key point. A general method which provides reliable molecular junctions with most metals remains to be found. In this paper we show that reliable molecular junctions Au/hexadecanethiol/n-GaAs(100) are obtained using buffer-layer-assisted growth (BLAG). They show in hot electron transport measurements at the nanoscale a tunnel regime through the organic monolayer with a full spatial uniformity. Using ballistic electron emission microscopy (BEEM) in the spectroscopic mode as well as photoemission and C(V)-transport measurements, we draw a coherent band alignment scheme of the whole heterostructure at the nanoscale and at the macroscopic scale. Through this study, the BLAG method appears as a general method that should work for contacting organic monolayers with most metals. © 2016 American Chemical Society.

Published
2016
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8. Formation of a body-centered-cubic Fe-based alloy at the Fe ∕ GaAs(001) interface

Author

B. Lépine, Claude Lallaizon, Guy Jézéquel, Philippe Schieffer, D. Sébilleau, A. Guivarc'h, Pascal Turban, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Diffraction, [PHYS]Physics [physics], Materials science, Physics and Astronomy (miscellaneous), Alloy, 02 engineering and technology, engineering.material, Cubic crystal system, 021001 nanoscience & nanotechnology, Epitaxy, 01 natural sciences, Crystallography, X-ray photoelectron spectroscopy, Electron diffraction, 0103 physical sciences, engineering, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, Layer (electronics), Deposition (law), ComputingMilieux_MISCELLANEOUS
Abstract

The room temperature epitaxial growth of Fe films on the As-rich GaAs(001)-(2×4) surface is studied using x-ray photoelectron spectroscopy as well as reflection high-energy electron diffraction and photoelectron diffraction. Interdiffusion mechanisms take place between Fe and GaAs during the deposition of the first 4 ML (0.7nm) Fe. The authors find that an Fe-based substitutional alloy with a body-centered-cubic structure confined on several atomic planes and containing 30% of foreign species (Ga and As atoms) sits at the Fe∕GaAs(001) interface. This intermixed layer is then buried by an almost pure Fe layer.

Published
2006
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9. Band structure of the epitaxial Fe/MgO/GaAs(001) tunnel junction studied by x-ray and ultraviolet photoelectron spectroscopies

Author

J. C. Le Breton, Philippe Schieffer, Yuan Lu, Guy Jézéquel, Pascal Turban, B. Lépine, Evolution et Diversité Biologique (EDB), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Physique des atomes, lasers, molécules et surfaces (PALMS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées

Subjects
010302 applied physics, [PHYS]Physics [physics], Condensed Matter - Materials Science, Materials science, Physics and Astronomy (miscellaneous), Schottky barrier, Fermi level, Analytical chemistry, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Heterojunction, Epitaxy, 01 natural sciences, [SPI.TRON]Engineering Sciences [physics]/Electronics, symbols.namesake, Band bending, Tunnel junction, 0103 physical sciences, symbols, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, Electronic band structure, ComputingMilieux_MISCELLANEOUS, Ultraviolet photoelectron spectroscopy
Abstract

International audience; The electronic band structure in the epitaxial Fe∕MgO∕GaAs(001) tunnel junction has been studied by x-ray and ultraviolet photoelectron spectroscopy measurements. The Schottky barrier height (SBH) of Fe on MgO∕GaAs heterostructure is determined to be 3.3±0.1eV, which sets the Fe Fermi level at about 0.3eV above the GaAs valence band maximum. This SBH is also exactly the same as that measured from Fe on MgO monocrystal. After Fe deposition, no band bending change is observed in MgO and GaAs underlayers. On the contrary, Au and Al depositions led to clear variation of the band bending in both MgO and GaAs layers. This effect is analyzed as a fingerprint of defect states at the MgO∕GaAs interface.

Published
2006
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10. Measurement of the valence-band offset at the epitaxial MgO-GaAs(001) heterojunction by x-ray photoelectron spectroscopy

Author

Yuan Lu, Guy Jézéquel, Pascal Turban, Philippe Schieffer, B. Lépine, J. C. Le Breton, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics and Astronomy (miscellaneous), Band gap, 02 engineering and technology, Electron hole, 01 natural sciences, Band offset, Condensed Matter::Materials Science, Condensed Matter::Superconductivity, 0103 physical sciences, Physics::Atomic and Molecular Clusters, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Electronic band structure, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, [PHYS]Physics [physics], Valence (chemistry), business.industry, Chemistry, Heterojunction, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, Semimetal, Optoelectronics, Direct and indirect band gaps, Atomic physics, 0210 nano-technology, business
Abstract

The electronic band structure at the interface of the MgO-GaAs(001) tunnel contact has been experimentally studied. X-ray photoelectron spectroscopy has been used to measure the valence-band offset at the MgO-GaAs(001) heterojunction interface. The valence-band offset ΔEV is determined to be 4.2±0.1eV. As a consequence, a nested “type-I” band alignment with a conduction-band offset of ΔEC=2.2±0.1eV is found. The accurate determination of the valence and conduction band offsets is important for the fundamental understanding of the tunnel spin injection in GaAs.

Published
2006
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11. Fe3GaAs/GaAs(0 01): a stable and magnetic metal-semiconductor heterostructure

Author

G. Jézéquel, Stéphanie Députier, F. Abel, A. Guivarc'h, André Rocher, C. Cohen, B. Lépine, Philippe Schieffer, F. Nguyen Van Dau, Claude Lallaizon, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Centre d'élaboration de matériaux et d'études structurales (CEMES), 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)-Centre National de la Recherche Scientifique (CNRS), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Groupe de Physique des Solides (GPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), 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-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), 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), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Annealing (metallurgy), Analytical chemistry, 02 engineering and technology, Epitaxy, 7. Clean energy, 01 natural sciences, Gallium arsenide, chemistry.chemical_compound, 0103 physical sciences, Silicide, Materials Chemistry, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Phase diagram, 010302 applied physics, [PHYS]Physics [physics], business.industry, Metals and Alloys, Heterojunction, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry, Transmission electron microscopy, Optoelectronics, 0210 nano-technology, business, Ternary operation
Abstract

International audience; We show that in agreement with the ternary Fe–Ga–As phase diagram, the solid-state interdiffusions in epitaxial Fe/GaAs(0 0 1) heterostructures lead, at a temperature of approximately 500 °C, to the formation of thermodynamically stable Fe3GaAs/GaAs(0 0 1) contacts quite similar to the well-known silicide/Si ones. The Fe3GaAs films are made of grains epitaxial on GaAs with a well-defined interface. Their magnetic and electrical properties make Fe3GaAs on GaAs an attractive metallization scheme for future magnetoelectronic devices. The results we report concern (25 or 80 nm Fe)/GaAs(0 0 1) heterostructures annealed at 480 and 500 °C for 10 min and characterized ex situ by He+ Rutherford backscattering and ion channeling, X-ray diffraction, transmission electron microscopy and alternating gradient field magnetometry.

Published
2004
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12. Epitaxial growth of Fe films on cubic GaN(001)

Author

Philippe Schieffer, C. Cohen, B. Lépine, F. Nguyen Van Dau, B. Daudin, A. Guivarc'h, Claude Lallaizon, F. Abel, G. Feuillet, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Groupe de Physique des Solides (GPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Diffraction, [PHYS]Physics [physics], Photoemission spectroscopy, Chemistry, Analytical chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Epitaxy, Rutherford backscattering spectrometry, 01 natural sciences, Inorganic Chemistry, Magnetization, Crystallography, Electron diffraction, 0103 physical sciences, Materials Chemistry, Thin film, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Molecular beam epitaxy
Abstract

Fe films have been grown on cubic GaN(0 0 1) layers by molecular beam epitaxy. They were studied in situ by reflection high-energy electron diffraction, X-ray photoemission spectroscopy and X-ray photoelectron diffraction and ex situ by Rutherford backscattering spectrometry (RBS), X-ray diffraction and alternating gradient field magnetometry. Despite the large lattice mismatch between Fe and cubic GaN [Δa/a=(2aFe−aGaN)/aGaN=+26%], the growth of Fe on GaN was found to be epitaxial with the orientation relationship (0 0 1)[1 0 0]Fe∥(0 0 1)[1 1 0]GaN i.e. with a 45° rotation of the Fe unit cell with respect to the GaN one. The mosaic spread of the Fe film does not exceed 1°. In such conditions we observed that the magnetic hysteresis loops show a cubic anisotropy with the easy axes along 〈1 0 0〉, as for bulk bcc Fe.

Published
2002
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13. Substrate disruption and surface segregation for Fe/InAs()

Author

Philippe Schieffer, B. Lépine, G. Jézéquel, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], Reflection high-energy electron diffraction, Chemistry, Fermi level, Analytical chemistry, 02 engineering and technology, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Epitaxy, 01 natural sciences, Surfaces, Coatings and Films, Overlayer, symbols.namesake, Electron diffraction, X-ray photoelectron spectroscopy, 0103 physical sciences, Materials Chemistry, symbols, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, Surface reconstruction, ComputingMilieux_MISCELLANEOUS, Molecular beam epitaxy
Abstract

The epitaxial growth of ultrathin Fe films on InAs(0 0 1)-(2×4) and -(4×2) surfaces at room temperature is studied using reflection high-energy electron diffraction as well as ultraviolet and X-ray photoelectron spectroscopy. The InAs(0 0 1)-(2×4) and -(4×2) surfaces are obtained either by ion bombardment and annealing or by molecular beam epitaxy. For the different surfaces a detailed analysis of the In 4d core-level line shape leads to the same conclusion. The deposition of Fe onto InAs(0 0 1) induces a substrate disruption and a surface segregation: in a first step In atoms are released in the metallic overlayer and with increasing the Fe coverage these In atoms continue to segregate at the surface. At the same time, some In atoms are trapped in the Fe overlayer. A small amount of As surface segregation is also observed. Finally, the position of the Fermi level (independent of the surface reconstruction and the preparation method) at the Fe/InAs(0 0 1) interfaces is found ∼0.2 eV above the conduction band minimum.

Published
2002
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14. Electric field effect on magnetic properties of ferromagnetic/SrTiO3(001) interfaces

Author

Mordret, Julien, Viel, Alexandra, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], PhDtitle, [PHYS] Physics [physics]
Abstract

supervisors Philippe Schieffer and Sylvain Tricot (department of materials - nanosciences), sous la direction de Philippe Schieffer et de Sylvain Tricot dans le département Matériaux-Nanosciences

Published
2021

15. PhD in progress : Ingénierie d'interface du silicium par des matériaux 2D [Defense 14.12.2020]

Author

Jules, Courtin, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Viel, Alexandra, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], PhDtitle, Soutenance2020, [PHYS] Physics [physics]
Abstract

supervisor Philippe Schieffer department of materials - nanosciences), sous la direction de Philippe Schieffer dans le département Matériaux-Nanosciences

Published
2017

16. PhD in progress :Caractérisations avancées des propriétés électroniques et structurales de matériaux III - V intégrés sur silicium [Defense : cancelled]

Author

Charbonnier, Simon, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics]
Abstract

supervisors Pascal Turban and Philippe Schieffer (department of materials - nanosciences); sous la direction de Pascal Turban et de Philippe Schieffer dans le département Matériaux-Nanosciences

Published
2015

17. Formation de l'interface Fe/SrTiO₃(001) : propriétés électroniques et structurales [Defense 26.11.2018]

Author

Catrou, Pierre, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Viel, Alexandra

Subjects
[PHYS]Physics [physics], PhDtitle, Soutenance2018, [PHYS] Physics [physics]
Abstract

supervisor Philippe Schieffer (department of soft matter), sous la direction de Philippe Schieffer dans le département matière molle

Published
2015

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