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1. Optical and structural properties of In-rich InxGa1−xAs epitaxial layers on (1 0 0) InP for SWIR detectors

Author

Marwa Ben Arbia, F. Saidi, Hassen Maaref, Fredj Hassen, Demir Ilkay, Altuntas Ismail, Zied Othmen, Brahim Dkhil, Elagoz Sezai, Badreddine Smiri, 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)-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), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Cumhuriyet University [Sivas, Turkey], Institut Supérieur des Sciences Appliquées et de Technologie de Sousse (ISSATS), Université de Sousse, Laboratoire Structures, Propriétés et Modélisation des solides (SPMS), Institut de Chimie du CNRS (INC)-CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), 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), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
PL, Photoluminescence, Materials science, Band gap, Residual stress, chemistry.chemical_element, 02 engineering and technology, Epitaxy, 01 natural sciences, symbols.namesake, Lattice mismatch, 0103 physical sciences, Dislocation, General Materials Science, Metalorganic vapour phase epitaxy, HR-XRD, Raman, 010302 applied physics, [PHYS]Physics [physics], business.industry, Mechanical Engineering, Rich indium content, Heterojunction, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Blueshift, Carrier localization, chemistry, Mechanics of Materials, symbols, Optoelectronics, 0210 nano-technology, Raman spectroscopy, business, Indium
Abstract

International audience; In-rich InxGa1−xAs epitaxial layers were grown on InP (1 0 0) substrates by a metalorganic vapor phase epitaxy (MOVPE) technique. The effect of Indium (In) composition on the crystalline quality and optical properties are investigated. High resolution X-ray diffraction (HR-XRD) measurement and Raman scattering spectrum are used to evaluate the crystalline quality, the residual strain and dislocation density property. The number of dislocations in the epitaxial layers is found to increase by increasing the Indium content in order to release the stresses due to the epitaxial clamping. Photoluminescence (PL) measurement is used to characterize the optical properties. At 10 K, PL measurements show that the InGaAs band gap redshifts with the indium content. Moreover, the asymmetry at the low-energy side of the PL peak has been attributed to the presence of localized excitons. In all samples, a blue shift of PL peaks is evidenced by increasing the excitation power density, which is in line with the presence of carrier’s localization and non-idealities in this system. Moreover, the temperature-dependence of the PL peak energy displays an unusual red-blue-red shift (S-shaped) behavior when raising the temperature. These observations can be related to the inhomogeneous distribution of indium which gives rise to the appearance of dislocations and other defects which serve as traps for charge carriers. Interestingly, those highly In-content InxGa1−xAs epitaxial layers show PL emission located between 1637 and 1811 nm (depending on In content) and thus might be suitable for in the design of novel heterostructure devices such as short wave infrared (SWIR) detectors.

Published
2020

2. Templated dewetting of single-crystal sub-millimeter-long nanowires and on-chip silicon circuits

Author

Meher Naffouti, Antonio M. Mio, Monica Bollani, Mario Lodari, Jean-Benoît Claude, Marco Salvalaglio, Marco Abbarchi, Ibtissem Fraj, Antoine Ronda, David Grosso, Mohammed Bouabdellaoui, Isabelle Berbezier, Luc Favre, Stefano Di Corato, A. Benali, Axel Voigt, Alexey V. Fedorov, Giuseppe Nicotra, Institute of Photonics and Nanotechnologies (CNR-IFN), ICT Institute of Politecnico di Milano, Institute of Scientific Computing, Department of Mathematics, Technische Universität Dresden = Dresden University of Technology (TU Dresden), Laboratory of Physics of Condensed Matter and Renewable Energy, Faculty of Sciences and Technology, Hassan II University of Casablanca, 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), CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Department of Geology & Geophysics, Yale University [New Haven], Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Laboratoire Pierre Aigrain (LPA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Electron mobility, Materials science, Silicon, Science, Nanowire, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, Hardware_PERFORMANCEANDRELIABILITY, 010402 general chemistry, 01 natural sciences, Article, General Biochemistry, Genetics and Molecular Biology, Si nanowires, law.invention, Monocrystalline silicon, law, Electronic devices, Hardware_INTEGRATEDCIRCUITS, Dewetting, lcsh:Science, Electronic circuit, Si dewetting, Multidisciplinary, Nanowires, business.industry, Transistor, General Chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, lcsh:Q, phase field simulation, Photonics, 0210 nano-technology, business, Hardware_LOGICDESIGN
Abstract

Large-scale, defect-free, micro- and nano-circuits with controlled inter-connections represent the nexus between electronic and photonic components. However, their fabrication over large scales often requires demanding procedures that are hardly scalable. Here we synthesize arrays of parallel ultra-long (up to 0.75 mm), monocrystalline, silicon-based nano-wires and complex, connected circuits exploiting low-resolution etching and annealing of thin silicon films on insulator. Phase field simulations reveal that crystal faceting and stabilization of the wires against breaking is due to surface energy anisotropy. Wires splitting, inter-connections and direction are independently managed by engineering the dewetting fronts and exploiting the spontaneous formation of kinks. Finally, we fabricate field-effect transistors with state-of-the-art trans-conductance and electron mobility. Beyond the first experimental evidence of controlled dewetting of patches featuring a record aspect ratio of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim$$\end{document}~1/60000 and self-assembled \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim$$\end{document}~mm long nano-wires, our method constitutes a distinct and promising approach for the deterministic implementation of atomically-smooth, mono-crystalline electronic and photonic circuits., Fabricating defect-free micro- and nano-circuits over large scales with controlled interconnections remains a challenge. Here, Bollani et al. show a dewetting strategy for engineering arrays of parallel Si-based nanowires up to 0.75 mm and complex interconnected circuits of monocrystalline Si on a chip.

Published
2019

3. Hole trap, leakage current and barrier inhomogeneity in (Pt/Au)-Al0.2Ga0.8N/GaN heterostructures

Author

Olfa Fathallah, Christophe Gaquiere, Hassen Maaref, Fethi Albouchi, Mohamed Mongi Ben Salem, Salah Saadaoui, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Faculty of Science and art KKU Mahail Assir, King Khalid University, Saudi Arabia, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Puissance - IEMN (PUISSANCE - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), and AcknowledgmentsThis work has been supported by 'Comité Mixte de Coopération Universitaire (CMCU) France-Tunisie' under the project '08G1305' between the IEMN-Lille and the LMON Monastir University

Subjects
Ideality factor, Materials science, Deep-level transient spectroscopy, 02 engineering and technology, Activation energy, 010402 general chemistry, Inhomogeneity, 01 natural sciences, Trap (computing), [SPI]Engineering Sciences [physics], General Materials Science, Deep traps, Equivalent series resistance, Condensed matter physics, Barrier height, Schottky diode, Heterojunction, AlGaN/GaN HEMT, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Leakage current, Dislocation, 0210 nano-technology, Layer (electronics)
Abstract

International audience; In this work, we report on the electrical characteristics of Pt/Au Schottky contacts to Al0.2Ga0.8N/GaN heterostructures. Indeed, we have realized gate current-voltage I(V) and deep level transient spectroscopy (DLTS) measurements. The behavior study of series resistance RS, ideality factor n, the effective barrier height Φb and leakage current with the temperature have emphasize barrier height inhomogeneity and extended defect in the (Pt/Au)Al0.2Ga0.8N/GaN system. The abnormal behavior of all these parameters can be attributed to the presence of traps thermally activated. Using the DLTS technique, we have detected one hole trap having an activation energy of 0.28eV and a capture cross-section of 1.9 × 10-19cm2. This trap should be a threading dislocation extending from the GaN layer to the surface.

Published
2019

4. High Frequency Analysis and Small-Signal Modeling of AlGaN/GaN HEMTs with SiO2/SiN Passivation

Author

Christophe Gaquiere, M. Gassoumi, Abdelhamid Helali, Hassen Maaref, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Qassim University [Kingdom of Saudi Arabia], Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Puissance - IEMN (PUISSANCE - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), and The authors gratefully acknowledge Qassim University, represented by the Deanship of Scientific Research, on the material support for this research under the number (3286)

Subjects
Materials science, Silicon, Passivation, chemistry.chemical_element, AlGaN/GaN/Si HEMTs, 02 engineering and technology, High-electron-mobility transistor, Trapping, 01 natural sciences, 7. Clean energy, law.invention, [SPI]Engineering Sciences [physics], law, 0103 physical sciences, Equivalent circuit parameters, 010302 applied physics, Frequency analysis, business.industry, Transistor, Small signal modeling, 021001 nanoscience & nanotechnology, Electronic, Optical and Magnetic Materials, [SPI.TRON]Engineering Sciences [physics]/Electronics, chemistry, Radio-frequency, Optoelectronics, 0210 nano-technology, business, Microwave, Molecular beam epitaxy
Abstract

International audience; AlGaN/GaN high electron mobility transistors (HEMTs) on Silicon substrates grown by molecular beam epitaxy have been investigated using small-signal microwave measurements, to see performance Radio-frequency of components. Passivation of HEMT devices SiO2/SiN a different pretreatment is used to reduce the effects of trapping and consequently has a large effect on these radio-frequency parameters. We used cold-FET and hot FET technique to extract the intrinsic and extrinsic parameters in order to show the effect passivation of parasitic elements; the parasitic capacitances, resistances and inductances. From this point we discover the extent of their impact on power and microwave performance.

Published
2019

5. Analysis of composition and microstructures of Ge grown on porous silicon using Raman spectroscopy and transmission electron microscopy

Author

Hassen Maaref, Isabelle Berbezier, Luc Favre, I. Jadli, Antoine Ronda, Gérard Panczer, Mansour Aouassa, L. Hassayoun, Laboratoire de Micro-optoélectronique et Nanostructures Faculté des Sciences de Monastir Université de Monastir, Institut Lumière Matière [Villeurbanne] ( ILM ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS ), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence ( IM2NP ), Aix Marseille Université ( AMU ) -Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), 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), and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
Materials science, Composite number, Analytical chemistry, 02 engineering and technology, Substrate (electronics), Ge growth, Porous silicon, 7. Clean energy, 01 natural sciences, symbols.namesake, 0103 physical sciences, General Materials Science, Electrical and Electronic Engineering, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], High-resolution transmission electron microscopy, 010302 applied physics, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, Transmission electron microscopy, Raman spectroscopy, symbols, 0210 nano-technology, Molecular beam epitaxy, [ PHYS.COND ] Physics [physics]/Condensed Matter [cond-mat]
Abstract

International audience; Composition and microstructure of Ge grown on porous silicon (PSi) by Molecular Beam Epitaxy (MBE) at different temperatures are examined using High Resolution Transmission Electron Microscopy (HRTEM) and Raman spectroscopy. Ge grown at 400 °C on PSi buffer produces a planar Ge film with high crystalline quality compared to Ge grown on bulk Si. This result is attributed to the compliant nature of PSi. Increasing growth temperature \textgreater600 °C, changes the PSi morphology, increase the Ge/Si intermixing in the pores during Ge growth and lead to obtain a composite SiGe/Si substrate. Ge content in the composite SiGe substrate can controlled via growth temperature. These substrates serve as low cost virtual substrate for high efficiency III–V/Si solar cells.

Published
2017

6. Photoluminescence and time-resolved photoluminescence studies of lateral carriers transfer among InAs/GaAs quantum dots

Author

Zaaboub, Z., Hassen, F., Naffouti, M., Marie, Xavier, M’ghaieth, R., Maaref, H., Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), College of Sciences, King Khalid University, 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), 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), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Condensed Matter::Materials Science, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Time resolved photoluminescence, Condensed Matter::Other, Quantum dots, Tunneling, Physics::Optics, [CHIM]Chemical Sciences, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Photoluminescence
Abstract

International audience; We report on the lateral transfer and thermal escape of carriers in InAs quantum dots (QDs) grown on a GaAs substrate by solid source molecular beam epitaxy by mean of photoluminescence (PL) and time-resolved PL measurements. The temperature-dependent PL spectra are discussed in terms of the inhomogeneous size distribution of the QDs and the carrier tunneling process from small to large QDs. The dependence of the photoluminescence decay time on the emission-wavelength is attributed to lateral carriers’ transfer within QDs with an interdot carrier tunneling time of 910 ps under low excitation conditions.

Published
2017

7. Investigation of the localization phenomenon in quaternary BInGaAs/GaAs for optoelectronic applications

Author

Faouzi Saidi, Tarek Hidouri, R. Hamila, Ibtissem Fraj, Laurent Auvray, Hassen Maaref, Philippe Rodriguez, Laboratoire de micro-optoelectronique et nanostructures, Université de Monastir - University of Monastir (UM), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Diffraction, Photoluminescence, Materials science, business.industry, Band gap, Exciton, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Condensed Matter::Materials Science, Full width at half maximum, 0103 physical sciences, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, General Materials Science, Metalorganic vapour phase epitaxy, Electrical and Electronic Engineering, 0210 nano-technology, business, Spectroscopy, Quantum well, ComputingMilieux_MISCELLANEOUS
Abstract

In this paper, single quantum well (SQW) structure of BxInyGa1-x-yAs/GaAs lattice-matched to GaAs has been grown by metal organic vapor phase epitaxy (MOVPE). The sample was characterized morphologically and structurally using the atomic force microscopy AFM, transmission electron microscopy TEM and high resolution X-ray diffraction HRXRD measurements. The optical study was investigated by photoluminescence (PL) spectroscopy as a function of temperature. The PL peak energy, the full width at half maximum (FWHM) and the PL intensity, versus temperature, exhibit anomalous behaviors such as S-shaped and N-shaped. They were attributed to the creation of a fluctuation potential in the band edge of the host material from the non-uniform distribution of boron atoms in the structure induced exciton localization. We investigate the localization phenomenon by excitation density variation. Then, a quasi-steady state rate-equation model for temperature dependent luminescence spectra of localized-state material system (LSE) was presented to quantitatively reinterpret the band gap emission process. The novel analytical models, compared with the classical ones, were used to fit the PL peak energy evolution. Good agreement between experimental and theoretical results has been observed using the modified Passler model. Modeling results will be discussed based on specified parameters. These results can improve the fundamental properties of quaternary based on light-emitting and optoelectronic devices.

Published
2017

8. Carrier dynamics of strain-engineered InAs quantum dots with (In)GaAs surrounding material

Author

Nicolas Chauvin, Bouraoui Ilahi, Catherine Bru-Chevallier, L. Sfaxi, Olfa Nasr, M.H. Hadj Alouane, Hassen Maaref, INL - Spectroscopies et Nanomatériaux (INL - S&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), and Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM)

Subjects
Materials science, Nanostructure, Photoluminescence, Nanotechnology, 02 engineering and technology, Epitaxy, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Optics, 0103 physical sciences, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, [PHYS]Physics [physics], [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Strain (chemistry), business.industry, Carrier lifetime, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Quantum dot, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, 0210 nano-technology, business, Luminescence, Excitation
Abstract

International audience; no abstract

Published
2017

9. LSE investigation of the thermal effect on band gap energy and thermodynamic parameters of BInGaAs/GaAs Single Quantum Well

Author

Tarek Hidouri, Ph. Rodriguez, Laurent Auvray, Faouzi Saidi, Hassen Maaref, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Photoluminescence, Band gap, 02 engineering and technology, Chemical vapor deposition, 01 natural sciences, 7. Clean energy, [SPI.MAT]Engineering Sciences [physics]/Materials, Inorganic Chemistry, Delocalized electron, 0103 physical sciences, Thermal, Metalorganic vapour phase epitaxy, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, Spectroscopy, Quantum well, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Condensed matter physics, Chemistry, Organic Chemistry, Atmospheric temperature range, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, 0210 nano-technology
Abstract

In this paper, we report on the experimental and theoretical study of BInGaAs/GaAs Single Quantum Well elaborated by Metal Organic Chemical Vapor Deposition (MOCVD). We carried out the photoluminescence (PL) peak energy temperature-dependence over a temperature range of 10–300 K. It shows the S-shaped behavior as a result of a competition process between localized and delocalized states. We simulate the peak evolution by the empirical model and modified models. The first one is limited at high PL temperature. For the second one, a correction due to the thermal redistribution based on the Localized State Ensemble model (LSE). The new fit gives a good agreement between theoretical and experimental data in the entire temperature range. Furthermore, we have investigated an approximate analytical expressions and interpretation for the entropy and enthalpy of formation of electron-hole pairs in quaternary BInGaAs/GaAs SQW.

Published
2016

10. Spatially resolved investigation and control of the bistability in single crystals of the [Fe(bbpya)(NCS)2] spin crossover complex

Author

William Nicolazzi, E. Hernández, Azzedine Bousseksou, Gábor Molnár, Karl Ridier, Víctor Velázquez, Helena J. Shepherd, Sipeng Zheng, Salma Bedoui, Dmitry S. Yufit, Sylvestre Bonnet, Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Leiden Institute of Chemistry (Leiden University), Universiteit Leiden [Leiden], School of Physical Sciences, University of Kent, Chemistry Department, Durham University, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), 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)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), and Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM)

Subjects
Phase boundary, 010405 organic chemistry, Chemistry, Spin transition, Nucleation, Triclinic crystal system, 01 natural sciences, Molecular physics, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Crystal, Crystallography, symbols.namesake, General Energy, Spin crossover, 0103 physical sciences, symbols, QD, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, 010306 general physics, Raman spectroscopy, Monoclinic crystal system
Abstract

International audience; The spin transition in single crystals of the [FeII(bbpya) (NCS)2] (bbpya = N,N-bis(2–2′-bipyrid-6-yl)amine) mononuclear complex was investigated by a combination of X-ray diffraction, Raman spectroscopy, as well as optical and atomic force microscopy (AFM) methods. These studies, performed around 440 K, revealed an extremely abrupt spin transition associated with a structural phase transition from a triclinic (low spin) to a monoclinic (mixed low spin/high spin) structure. Spatially resolved observations of this transition evidenced a clear phase separation associated with heterogeneous nucleation and the formation of a moving macroscopic interface whose velocity reached in some cases 300 μm s–1. Using photothermal control it was possible to stabilize biphasic states of the crystal and then acquire AFM images of the phase boundary. A “sawtooth” like topography was repeatedly observed, which most likely emerges so as to minimize the elastic strain. Remarkably, a fine spatial control of the phase boundary could be also achieved using the AFM probe itself, through probe–sample convective heat exchange.

Published
2016

11. Effect of Passivation on Microwave Power Performances of AlGaN/GaN/Si HEMTs

Author

Mosbahi, H., Charfeddine, M., Gassoumi, M., Mejri, H., Gaquière, Christophe, Grimbert, Bertrand, Zaidi, M.A., Maaref, H., Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire d'Electronique et de Microélectronique [Monastir] (EμE), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Subjects
SiO2/SiN Passivation, lcsh:Technology (General), Pulse measurements, AlGaN/GaN HEMTs, lcsh:T1-995
Abstract

This paper reports on the use of plasma assisted molecular beam epitaxy of AlGaN/GaN high electron mobility transistors (HEMTs) grown on silicon substrate. Surface passivation effects on AlGaN/GaN HEMTs were studied using SiO2/SiN dielectric layers grown by plasma enhanced chemical vapor deposition. The direct current measurement, pulsed characteristics and microwave small-signal characteristics were studied before and after passivation. An improvement of drain-source current density and the extrinsic transconductance was observed on the passivated HEMTs when compared with the unpassivated HEMTs. An enhancement of cut-off frequency (ft) and maximum power gain (fmax) was also observed for the devices with full SiO2/SiN passivation. A good correlation is found between pulsed and power measurements. Copyright © 2014 IFSA Publishing, S. L.

Published
2014

12. Fe(Me-2-bpy)(2)(NCSe)(2) spin-crossover micro- and nanoparticles showing spin-state switching above 250 K

Author

Salma Bedoui, Eric Rivière, Régis Guillot, Gábor Molnár, Lionel Rechignat, Marie-Laure Boillot, Jérôme Laisney, Luong Lam Nguyen, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), 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)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Groupe de spectrométrie moléculaire et atmosphérique (GSMA), and Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Precipitation (chemistry), Chemistry, Stereochemistry, Thermal decomposition, Analytical chemistry, Nanoparticle, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Catalysis, 0104 chemical sciences, Crystallinity, symbols.namesake, Spin crossover, Materials Chemistry, symbols, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Crystallite, 0210 nano-technology, Raman spectroscopy, Dispersion (chemistry)
Abstract

International audience; We present the study of nano- and microparticles of the Fe(Me-2-bpy)(2)(NCSe)(2) spin-crossover complex prepared from the diamagnetic precursor [Fe(Me-2-bpy)(3)](NCSe)(2)center dot S. Two solvates of the latter were characterized by single-crystal X-ray structures at 100 K (S = 2MeOH or 3H(2)O). The extraction of one Me-2-bpy per metal ion in [Fe(Me-2-bpy)(3)](NCSe)(2)center dot S was achieved either by thermolysis at temperature higher than 150 degrees C or by precipitation in an anti-solvent, leading to a polycrystalline or particulate powder of Fe(Me-2-bpy)(2)(NCSe)(2). This chemical conversion was investigated by TGA, powder X-ray diffraction, IR, Raman and magnetic measurements. The S = 0 S = 2 spin-crossover of Fe(Me-2-bpy)(2)-(NCSe)(2) centered at ca. 340 K is almost complete at low temperature (HS residue

Published
2015

13. Impact of single crystal properties on nucleation and growth mechanisms of a spin transition

Author

Sylvestre Bonnet, Salma Bedoui, Azzedine Bousseksou, Sipeng Zheng, William Nicolazzi, Gábor Molnár, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), 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)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Leiden Institute of Chemistry (Leiden University), and Universiteit Leiden [Leiden]

Subjects
Nucleation and growth, Condensed matter physics, Chemistry, Nucleation, Spin transition, Microstructure, Optical microscopy, 3. Good health, law.invention, Micro-structural defects, Inorganic Chemistry, Crystal, Optical microscope, law, Spin crossover, Materials Chemistry, Single crystals, Condensed Matter::Strongly Correlated Electrons, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Single crystal, Spin-½
Abstract

We have investigated the spatio-temporal development of the spin transition in different single crystals of the molecular complex [Fe(bapbpy)(NCS)2] using optical microscopy. The thermal spin transition proceeds by nucleation at macroscopic defects, followed in most cases by anisotropic growth. We show that a lower crystalline quality leads to multi-site nucleation and intermittent spin transitions. We conclude that each crystal of a same spin crossover complex can have its proper spin transition kinetics depending on its crystalline properties and intrinsic microstructure.

Published
2015

14. Carriers' localization and thermal redistribution in post growth voluntarily tuned quantum dashes' size/composition distribution

Author

Hadj Alouane M, H., Helali, A., Morris, D., Maaref, H., Aimez, Vincent, Salem, B., Gendry, Michel, Ilahi, B., Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), INL - Spectroscopies et Nanomatériaux (INL - S&N), Institut des Nanotechnologies de Lyon (INL), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), Institut Interdisciplinaire d'Innovation Technologique [Sherbrooke] (3IT), Université de Sherbrooke (UdeS), Laboratoire des technologies de la microélectronique (LTM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), INL - Hétéroepitaxie et Nanostructures (INL - H&N), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Inl, Laboratoire INL UMR5270

Subjects
[SPI]Engineering Sciences [physics], [SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic, [SPI] Engineering Sciences [physics], [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, ComputingMilieux_MISCELLANEOUS, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract

International audience; no abstract

Published
2014

15. Improved photovoltaic performance of silicon nanowires/conjugated polymer hybrid solar cells

Author

Chehata, N., taief, L., Ilahi, A., Salem, B., Bouazizi, B., Maaref, A., Baron, T., Gentile, P., Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM), Laboratoire des technologies de la microélectronique (LTM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Silicon Nanoelectronics Photonics and Structures (SiNaps), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Polytechnique de Bordeaux (Bordeaux INP), Laboratoire d'automatique de Caen (LAC), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire de Physique et Chimie des Interfaces [Monastir] (LPCI), Ingénierie des Matériaux Polymères (IMP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Equipe Automatique - Laboratoire GREYC - UMR6072, Groupe de Recherche en Informatique, Image et Instrumentation de Caen (GREYC), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Photoluminescence, Materials science, Nanowire, Photovoltaic effect, Hybrid solar cells, Conjugated system, 7. Clean energy, Si nanowires, Materials Chemistry, Polymer, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, [PHYS]Physics [physics], Nanocomposite, business.industry, Mechanical Engineering, Photovoltaic system, Metals and Alloys, Hybrid solar cell, [CHIM.MATE]Chemical Sciences/Material chemistry, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Mechanics of Materials, Optoelectronics, business, Photoluminescence quenching
Abstract

International audience; In this study, we investigate the effect of incorporation of Si nanowires (SiNWs) on the organic/inorganic hybrid nanocomposites based on poly [2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) and SiNWs. A huge potential for SiNWs for an amelioration of optical properties of investigated structures was shown, and particularly a more efficient charge transfer was guaranteed. The impact of SiNWs incorporation on photoluminescence properties of polymer:Si nanowires nanocomposites have been correlated with morphological characteristics. MEH-PPV:SiNWs (1:2) is the optimum composition where the device performance displays a Jsc of 0.328 μA/cm2, a Voc of 0.680 V and FF of 38%.

Published
2014

16. Optical characterization of wavelength tunable InAs QDs with (In)GaAs surrounding material

Author

Nasr, O., Hadj Alouane M, H., Chauvin, Nicolas, Maaref, H., Hassen, F., Bru-Chevallier, C., Sfaxi, L., Ilahi, B., INL - Spectroscopies et Nanomatériaux (INL - S&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), and Inl, Laboratoire INL UMR5270

Subjects
[SPI]Engineering Sciences [physics], [SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic, [SPI] Engineering Sciences [physics], [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

7-11 july 2014; International audience; no abstract

Published
2014

17. Piezoelectric effect in InAs/InP quantum rod nanowires grown on silicon substrate

Author

Catherine Bru-Chevallier, Nicolas Chauvin, Gilles Patriarche, H. Khmissi, Roman Anufriev, K. Naji, Michel Gendry, INL - Spectroscopies et Nanomatériaux (INL - S&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), INL - Hétéroepitaxie et Nanostructures (INL - H&N), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)

Subjects
Materials science, Physics and Astronomy (miscellaneous), Condensed matter physics, Condensed Matter::Other, Quantum-confined Stark effect, Nanogenerator, Nanowire, Physics::Optics, Heterojunction, Substrate (electronics), Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Piezoelectricity, [SPI.MAT]Engineering Sciences [physics]/Materials, Condensed Matter::Materials Science, symbols.namesake, [SPI]Engineering Sciences [physics], Stark effect, symbols, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, ComputingMilieux_MISCELLANEOUS, Wurtzite crystal structure
Abstract

We report on the evidence of a strain-induced piezoelectric field in wurtzite InAs/InP quantum rod nanowires. This electric field, caused by the lattice mismatch between InAs and InP, results in the quantum confined Stark effect and, as a consequence, affects the optical properties of the nanowire heterostructure. It is shown that the piezoelectric field can be screened by photogenerated carriers or removed by increasing temperature. Moreover, a dependence of the piezoelectric field on the quantum rod diameter is observed in agreement with simulations of wurtzite InAs/InP quantum rod nanowire heterostructures.

Published
2014

18. Quantum efficiency of InAs/InP nanowire heterostructures grown on silicon substrates

Author

Anufriev, Roman, Chauvin, Nicolas, KHMISSI, Hammadi, Naji, Khalid, Patriarche, Gilles, GENDRY, Michel, BRU-CHEVALLIER, Catherine, INL - Spectroscopies et Nanomatériaux (INL - S&N), Institut des Nanotechnologies de Lyon (INL), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), INL - Hétéroepitaxie et Nanostructures (INL - H&N), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Condensed Matter::Materials Science, [SPI]Engineering Sciences [physics], Condensed Matter::Other, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract

International audience; Photoluminescence (PL) quantum efficiency (QE) is experimentally investigated, using an integrating sphere, as a function of excitation power on both InAs/InP quantum rod nanowires (QRod-NWs) and radial quantum well nanowires (QWell-NWs) grown on silicon substrates. The measured values of the QE are compared with those of the planar analogues such as quantum dash and quantum well samples, and found to be comparable for the quantum well structures at relatively low power density. Further studies reveal that the values of QE of the QRod-NWs and QWell-NWs are limited by the low quality of the InP NW structure and the quality of radial quantum well, respectively.

Published
2013

19. The kinetics of dewetting ultra-thin Si layers from silicon dioxide

Author

Antoine Ronda, Luc Favre, Hassen Maaref, Mansour Aouassa, Isabelle Berbezier, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence ( IM2NP ), Aix Marseille Université ( AMU ) -Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Micro-optoélectronique et Nanostructures Faculté des Sciences de Monastir Université de Monastir, 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), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Surface diffusion, Amorphous silicon, Coalescence (physics), Physics, Silicon, Nucleation, General Physics and Astronomy, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Physics::Fluid Dynamics, Condensed Matter::Soft Condensed Matter, chemistry.chemical_compound, chemistry, Chemical physics, 0103 physical sciences, Dewetting, Crystalline silicon, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Silicon oxide, [ PHYS.COND ] Physics [physics]/Condensed Matter [cond-mat]
Abstract

International audience; In this study, we investigate the kinetically driven dewetting of ultra-thin silicon films on silicon oxide substrate under ultra-high vacuum, at temperatures where oxide desorption and silicon lost could be ruled out. We show that in ultra-clean experimental conditions, the three different regimes of dewetting, namely (i) nucleation of holes, (ii) film retraction and (iii) coalescence of holes, can be quantitatively measured as a function of temperature, time and thickness. For a nominal flat clean sample these three regimes co-exist during the film retraction until complete dewetting. To discriminate their roles in the kinetics of dewetting, we have compared the dewetting evolution of flat unpatterned crystalline silicon layers (homogeneous dewetting), patterned crystalline silicon layers (heterogeneous dewetting) and amorphous silicon layers (crystallization-induced dewetting). The first regime (nucleation) is described by a breaking time which follows an exponential evolution with temperature with an activation energy EH ∼ 3.2 eV. The second regime (retraction) is controlled by surface diffusion of matter from the edges of the holes. It involves a very fast redistribution of matter onto the flat Si layer, which prevents the formation of a rim on the edges of the holes during both heterogeneous and homogeneous dewetting. The time evolution of the linear dewetting front measured during heterogeneous dewetting follows a characteristic power law x ∼ t0.45 consistent with a surface diffusion-limited mechanism. It also evolves as x ∼ h−1 as expected from mass conservation in the absence of thickened rim. When the surface energy is isotropic (during dewetting of amorphous Si) the dynamics of dewetting is considerably modified: firstly, there is no measurable breaking time; secondly, the speed of dewetting is two orders of magnitude larger than for crystalline Si; and thirdly, the activation energy of dewetting is much smaller due to the different driving force, which is based on the crystallization and redistribution of matter around the crystalline nuclei. The third regime (coalescence) corresponds to the merging of the dewetted fronts and of the islands positioned along the edges of the holes. The dynamics of this regime is much slower since it requires overcoming an additional nucleation barrier, while the surface energy reduction is quite low (low decrease of the covered surface area).

Published
2012

20. Fermi edge singularity evidence from photoluminescence spectroscopy of AlGaAs/InGaAs/GaAs pseudomorphic HEMTs grown on (311)A GaAs substrates

Author

S., REKAYA, L., SFAXI, BRU-CHEVALLIER, C., H., MAAREF, BRU CHEVALLIER, Catherine, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), INL - Spectroscopies et Nanomatériaux (INL - S&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI]Engineering Sciences [physics], [SPI] Engineering Sciences [physics], [SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2011

21. Temperature dependence of optical properties of InAs/GaAs self-organized quantum dots

Author

Hassen Maaref, Catherine Bru-Chevallier, Olivier Marty, L. Sfaxi, M. Baira, L. Bouzaiene, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire d'Electronique, Nanotechnologies, Capteurs (LENAC), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, INL - Spectroscopies et Nanomatériaux (INL - S&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Photoluminescence, Materials science, Physics::Optics, General Physics and Astronomy, 02 engineering and technology, Electron, 01 natural sciences, 7. Clean energy, Spectral line, Gallium arsenide, Condensed Matter::Materials Science, chemistry.chemical_compound, [SPI]Engineering Sciences [physics], Effective mass (solid-state physics), 0103 physical sciences, Electronic band structure, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Condensed matter physics, Condensed Matter::Other, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, chemistry, Quantum dot, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, 0210 nano-technology, Molecular beam epitaxy
Abstract

Self-organized InAs/GaAs quantum dots (QDs) were grown by molecular beam epitaxy. The photoluminescence, its power, and temperature dependences have been studied for the ensembles of InAs QDs embedded in GaAs matrix to investigate the interband transition energies. Theoretical calculations of confined electron (heavy-hole) energy in the InAs/GaAs QDs have been performed by means of effective mass approximation, taking into account strain effects. The shape of the InAs QDs was modeled to be a convex-plane lens. The calculated interband transition energies were compared with the results of the photoluminescence spectra. The calculated interband transition energy from the ground electronic subband to the ground heavy-hole state was in reasonable agreement with the transition energy obtained by the photoluminescence measurement.

Published
2009

22. Clustering effects in optical properties of BGaAs/GaAs epilayers

Author

Hassen Maaref, Yves Monteil, R. Hamila, Faouzi Saidi, Laurent Auvray, A. Fouzri, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Quenching, [PHYS]Physics [physics], Photoluminescence, Chemistry, Doping, Biophysics, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, General Chemistry, Chemical vapor deposition, Activation energy, Atmospheric temperature range, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Biochemistry, Atomic and Molecular Physics, and Optics, 0103 physical sciences, Metalorganic vapour phase epitaxy, 0210 nano-technology, Boron, ComputingMilieux_MISCELLANEOUS
Abstract

We report on the further investigation of the effect of boron incorporation on GaAs grown at 580 °C temperature on GaAs (0 0 1) substrate by metal organic chemical vapor deposition (MOCVD). High-resolution X-ray diffraction (HRXRD) has been used to determine the lattice mismatch and to estimate the boron concentration. Temperature-dependent photoluminescence has been carried out to investigate B x Ga 1− x As/GaAs epilayers with varied boron composition ( x =1.64% and 3.04%). Low temperature (10 K) PL study has shown an asymmetric and broad PL band around 1.3 eV of the emission energies with a decrease of the PL intensity with increasing boron composition. The evolution of the emission energies with temperature can be described by Varshni law for the high temperature range ( T ⩾120 and 80 K) for boron composition x =1.64% and 3.04%, respectively, while a relative discrepancy has been found to occur at low temperature. Moreover, depending on the temperature range, the PL intensity quenching is found to be thermally ensured by three activation energies. These results are attributed to the localized states induced by the non-uniform insertion of boron and the clustering of the boron atom in BGaAs bulk.

Published
2009

23. Morphology and optical properties of p-type porous GaAs(100) layers made by electrochemical etching

Author

Georges Bremond, Mokhtar Hjiri, F. Saidi, Bernard Gruzza, Lotfi Beji, S. Ben Khalifa, Luc Bideux, Christine Robert-Goumet, Hassen Maaref, Institut Pascal (IP), SIGMA Clermont (SIGMA Clermont)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020]), Laboratoire des sciences et matériaux pour l'électronique et d'automatique (LASMEA), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de la matière (LPM), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), SIGMA Clermont (SIGMA Clermont)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Photoluminescence, Biophysics, Oxide, Analytical chemistry, 02 engineering and technology, 01 natural sciences, Biochemistry, chemistry.chemical_compound, X-ray photoelectron spectroscopy, 0103 physical sciences, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, Atomic and Molecular Physics, and Optics, chemistry, Nanocrystal, Quantum dot, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Crystallite, 0210 nano-technology, Porous medium
Abstract

Porous GaAs layers were formed by electrochemical etching of p-type GaAs(1 0 0) substrates in HF solution. A surface characterization has been performed on p-type GaAs samples using X-ray photoelectron spectroscopy (XPS) technique in order to get information about the chemical composition, particularly on the surface contamination. According to the XPS spectra, the oxide layer on as-received porous GaAs substrates contains As2O3, As2O5 and Ga2O3. Large amount of oxygen is present at the surface before the surface cleaning. Compared to untreated GaAs surface, room temperature photoluminescence (PL) investigations of the porous layers reveal the presence of two PL bands: a PL peak at ∼871 nm and a “visible” PL peak at ∼650–680 nm. Both peak wavelengths and intensities varied from sample to sample depending on the treatment that the samples have undergone. The short PL wavelength at 650–680 nm of the porous layers is attributed to quantum confinement effects in GaAs nano-crystallites. The surface morphology of porous GaAs has been studied using atomic force microscopy (AFM). Nano-sized crystallites were observed on the porous GaAs surface. An estimation of the mean size of the GaAs nano-crystals obtained from effective mass theory and based on PL data was close to the lowest value obtained from the AFM results.

Published
2008

24. Optical investigation of phosphorous-ion-implantation induced InAs/GaAs quantum dots' intermixing

Author

Bouraoui Ilahi, Denis Morris, L. Sfaxi, Bassem Salem, Z. Zaâboub, Vincent Aimez, Hassen Maaref, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire de micro-optoelectronique et nanostructures, Université de Monastir - University of Monastir (UM), Laboratoire des technologies de la microélectronique (LTM), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université de Sherbrooke (UdeS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Physics, Low temperature photoluminescence, Photoluminescence, Band gap, business.industry, General Physics and Astronomy, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Ion, Laser linewidth, Ion implantation, Quantum dot, 0103 physical sciences, Optoelectronics, Rapid thermal annealing, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 0210 nano-technology, business, ComputingMilieux_MISCELLANEOUS
Abstract

This work reports on InAs/GaAs quantum dots (QDs) intermixing, induced by phosphorous ion implantation and subsequent rapid thermal annealing. The implantation process was carried out at room temperature at various doses ( 5 × 10 10 – 10 14 ions / cm 2 ), where the ions were accelerated at 50 keV. To promote the atomic intermixing, implanted samples are subjected to rapid thermal annealing at 675 °C for 30 s. Low temperature photoluminescence (PL) measurements are carried out to investigate the influence of the interdiffusion process on the optical and electronic properties of the QDs. PL emission energy; linewidth and integrated intensity are found to exhibit a drastic dependence on the ion implantation doses. The band gap tuning limit has been achieved for an implantation dose of 5 × 10 13 ions / cm 2 . However, our measurement reveals that the accumulated defects for implantation doses higher than 10 12 ions / cm 2 drive the system towards the degradation of the QDs structure's quality.

Published
2008

25. Enhancement of the 2DEG density in AlGaAs/InGaAs/GaAs P-HEMTs structures grown by MBE on (311)A and (111)A GaAs substrates

Author

L. Sfaxi, Catherine Bru-Chevallier, S. Rekaya, Hassen Maaref, L. Bouzaiene, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), INL - Spectroscopies et Nanomatériaux (INL - S&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and BRU CHEVALLIER, Catherine

Subjects
Electron density, Photoluminescence, Materials science, [SPI] Engineering Sciences [physics], [SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Bioengineering, 02 engineering and technology, Substrate (electronics), High-electron-mobility transistor, Epitaxy, 01 natural sciences, 7. Clean energy, Biomaterials, Condensed Matter::Materials Science, [SPI]Engineering Sciences [physics], 0103 physical sciences, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Condensed matter physics, Heterojunction, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, Mechanics of Materials, 0210 nano-technology, Fermi gas, Molecular beam epitaxy
Abstract

The pseudomorphic high electron mobility transistor (P-HEMT) structure materials Al0.33Ga0.7As/In0.1Ga0.9As/GaAs have been grown by molecular beam epitaxy (MBE) on (311)A and (111)A GaAs substrates. The epitaxy of strain heterostructure on high index GaAs substrate has led to new growth phenomena, material properties and device applications. The photoluminescence (PL) spectra of the structures have been measured at low temperature. The dominant emission in the PL spectra is due to the recombination from the first electron (e1) subband to the first heavy-hole (hh1) subband (E11: e1–hh1). This feature (E11) is a relatively broad peak and has a typical asymmetric line shape. The transformation of the PL spectra in the close vicinity of the Fermi edge (EF) under different excitation densities gives strong evidence for the Fermi Edge Singularity (FES) existence. The density of the quasi-two-dimensional electron gas (2DEG) determined by PL study (nsPL), is in sufficient agreement with the values found from Hall measurements nsHall at 77 K. The results prove an increase of the electron density in sample grown on GaAs (111)A and (311)A rather than in equivalent sample grown on (001) GaAs substrate. This effect is in good agreement with our theoretical prediction, which is based on a self-consistent solution of the coupled Schrodinger and Poisson equations.

Published
2008

26. Optical characterisation of single InAs quantum dots on GaAs substrate emitting at 1.3 μm

Author

Nicolas Chauvin, Catherine Bru-Chevallier, Bouraoui Ilahi, Hassen Maaref, L. Sfaxi, M. Baira, Laboratoire de physique de la matière (LPM), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
Photoluminescence, Exciton, 02 engineering and technology, Substrate (electronics), 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Condensed Matter::Materials Science, [SPI]Engineering Sciences [physics], 0103 physical sciences, Emission spectrum, 010306 general physics, Spectroscopy, Biexciton, ComputingMilieux_MISCELLANEOUS, Condensed matter physics, Condensed Matter::Other, business.industry, Chemistry, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Quantum dot laser, Quantum dot, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, 0210 nano-technology, business
Abstract

Single InAs/GaAs quantum dots are studied using micro-photoluminescence spectroscopy. Single dot spectroscopy shows an antibinding biexciton. Some of these quantum dots are laterally coupled due to an anisotropic dot repartition. At low excitation power density, four excitons emissions are observed and are interpreted as the four possible exciton recombinations of two coupled quantum dots. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Published
2006

27. Optimizing the spacer layer thickness of vertically stacked InAs/GaAs quantum dots

Author

Olivier Marty, Bassem Salem, Hassen Maaref, Bouraoui Ilahi, L. Sfaxi, Georges Bremond, F. Hassen, L. Bouzaiene, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire des technologies de la microélectronique (LTM), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de la matière (LPM), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Electronique, Nanotechnologies, Capteurs (LENAC), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Laboratoire de micro-optoelectronique et nanostructures, Université de Monastir - University of Monastir (UM), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Photoluminescence, Yield (engineering), Materials science, Field (physics), business.industry, Bioengineering, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Biomaterials, Mechanics of Materials, Quantum dot, 0103 physical sciences, Optoelectronics, Coupling (piping), [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 010306 general physics, 0210 nano-technology, business, Spectroscopy, Excitation, ComputingMilieux_MISCELLANEOUS, Molecular beam epitaxy
Abstract

Vertically stacked multilayers of self-organized InAs/GaAs quantum dots (QDs) structures with different GaAs intermediate layer thicknesses varying between 2.8 and 17 nm are grown by solid source molecular beam epitaxy (SSMBE) and investigated by photoluminescence spectroscopy (PL). For 17 nm thick GaAs spacer, the PL spectra show two well separated features attributed to the formation of two QDs family with a bimodal size distribution indicating no correlation between the dots in different layers. In the meanwhile, the structures having thinner spacer thickness demonstrate single PL peaks showing an enhancement of high energy side asymmetrical broadening when increasing the excitation power. The corresponding emission energies exhibit a red shift when the spacer layer thickness decreases and correlated with the enhancement of the vertical electronic coupling as well as the rise of the QD's size in the upper layers induced by the build up of the strain field along the columns. The spacer thickness of 8.5 nm is found to yield the best optical properties.

Published
2006

28. Toward long wavelength low density InAs/GaAs quantum dots

Author

Georges Bremond, Hassen Maaref, L. Sfaxi, M. Baira, E. Tranvouez, Bouraoui Ilahi, C. Bru-Chevalier, Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire de Photophysique Moléculaire (PPM), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), INL - Spectroscopies et Nanomatériaux (INL - S&N), Institut des Nanotechnologies de Lyon (INL), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Photoluminescence, General Physics and Astronomy, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Blueshift, Full width at half maximum, [SPI]Engineering Sciences [physics], Quantum dot, Excited state, 0103 physical sciences, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Atomic physics, 010306 general physics, 0210 nano-technology, Spectroscopy, Deposition (law), ComputingMilieux_MISCELLANEOUS, Molecular beam epitaxy
Abstract

Optical and morphological properties of solid source molecular beam epitaxy (MBE) grown InAs/GaAs quantum dots are investigated by photoluminescence spectroscopy (PL) and atomic force microscopy (AFM) as a function of the growth rate. The 10 K relatively high excitation density PL spectra of the investigated samples reveal the existence of multipeaks characterizing fundamental states and corresponding excited states. The emission energies are red-shifted by approximately 70 meV, when the InAs deposition rate is reduced from 0.069 ML/s to 0.013 ML/s. By further reducing the growth rate down to 0.003 ML/s an unexpected blue shift of the emission energy occurs. AFM observations, carried out on similar uncapped samples, show a monotonic decrease of the QDs density with decreasing QDs material's deposition rate. For a growth rate of 0.003 ML/s, islands density of 4.9 × 10 9 cm −2 has been achieved with a room temperature PL full width at half maximum (FWHM) of 22 meV. For the later growth rate, the blue shift of the emission energy has been correlated with desorption of In atoms during InAs deposition.

Published
2006

29. Radiative N-localized recombination and confinement in GaAsN/GaAs epilayers and quantum well structures

Author

F. Hassen, Faouzi Saidi, Hassen Maaref, Yves Monteil, H. Dumont, Laurent Auvray, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), and Auvray, Laurent

Subjects
Photoluminescence, Materials science, Exciton, 02 engineering and technology, 01 natural sciences, [PHYS] Physics [physics], Inorganic Chemistry, Condensed Matter::Materials Science, 0103 physical sciences, Radiative transfer, Spontaneous emission, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, Spectroscopy, Quantum well, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, [PHYS]Physics [physics], Condensed matter physics, Condensed Matter::Other, Organic Chemistry, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Blueshift, 0210 nano-technology, Excitation, Recombination
Abstract

The photoluminescence (PL) properties of GaAsN/GaAs epilayers and single quantum wells (QWs) have been investigated as a function of the excitation density and the sample temperature (10–300 K). At low temperatures, the PL spectra were sensitive to the excitation density for epilayers and QWs. For both structures, a blue shift of the PL peak is noted with increasing the excitation power. In contrast, the temperature dependence shows different behaviors for the bulk epilayers and for the quantum wells structures. An S-shape of the PL peak energy versus temperature has been observed for the GaAsN/GaAs epilayer while the QWs peak energy decreases monotically with the sample temperature and could be fitted by conventional Varshni’s law. This behavior is due to the exciton localization effect which is induced by the local fluctuation of nitrogen concentration.

Published
2003

30. Excitons localization effects in GaAsN/GaAs epilayers grown by MOCVD

Author

Hassen Maaref, Faouzi Saidi, F. Hassen, Laurent Auvray, Yves Monteil, H. Dumont, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, [PHYS]Physics [physics], Range (particle radiation), Photoluminescence, Materials science, Exciton, Analytical chemistry, chemistry.chemical_element, Bioengineering, 02 engineering and technology, Chemical vapor deposition, Nanosecond, 021001 nanoscience & nanotechnology, 01 natural sciences, Nitrogen, Biomaterials, chemistry, Mechanics of Materials, 0103 physical sciences, Metalorganic vapour phase epitaxy, 0210 nano-technology, Recombination, ComputingMilieux_MISCELLANEOUS
Abstract

Optical studies of GaAs 1− x N x /GaAs epilayers grown by metal-organic chemical vapour deposition (MOCVD), with low nitrogen concentration (1.65% and 2.2%), have been achieved by a number of optical techniques such as photoluminescence (PL), photoreflectance (PR) spectroscopies and time-resolved PL (TR-PL) measurements in the nanosecond range. It has been shown that the increase of the nitrogen fraction causes a red shift of the PL emission band compared to the GaAs one. TR-PL results at 12 K reveal that the decay time is clearly dependent on the emission energy. It increases for lower emission energy. From the temperature PL decay lifetime study, we suggest that PL emission is dominated by the recombination of localized excitons trapped by potential fluctuations of the near band edge induced by compositional fluctuations in GaAsN epilayer.

Published
2002

31. Auger effect as the origin of the fast-luminescent band of freshly anodized porous silicon

Author

H. Maâref, I. Mihalcescu, J. C. Vial, R. M'ghaïeth, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Auger effect, Anodizing, 02 engineering and technology, 021001 nanoscience & nanotechnology, Porous silicon, 01 natural sciences, symbols.namesake, Chemical engineering, 0103 physical sciences, symbols, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, Luminescence, Porous medium, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
1999

32. Porous silicon: photoluminescence decay in the nanosecond range

Author

H. Maâref, J. C. Vial, I. Mihalcescu, R. M'ghaïeth, Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Range (particle radiation), Photoluminescence, Nanostructure, Materials science, Silicon, General Engineering, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, Nanosecond, 021001 nanoscience & nanotechnology, Porous silicon, 01 natural sciences, chemistry, 0103 physical sciences, Wafer, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Excitation, ComputingMilieux_MISCELLANEOUS
Abstract

Unlike the slow band (S-band), there is currently no clear spectroscopic signature which links the fast band (F-band) to the Si nanostructure. Time resolved photoluminescence (TRPL) was employed in the present work to study the porous silicon photoluminescence decay behavior in the nanosecond range, namely the F-band. Measurements were performed at room temperature on oxidized and fresh porous silicon samples. It was shown that the fast (ns) component had an extrinsic origin for oxidized samples, while the fresh samples exhibited an intrinsic behavior for both the fast and slow (10 μs) components. The excitation intensity dependence of the PL intensity was studied and showed different behavior of the F-band in both oxidized and fresh samples.

Published
1999

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