Showing papers by "Jean Massies published in 2006"
TL;DR: In this paper, the transition energy and the radiative lifetime of Wurtzite GaN/AlN quantum dots (QDs) are studied by time-resolved photoluminescence.
Abstract: Wurtzite GaN/AlN quantum dots (QDs) are studied by time-resolved photoluminescence. Careful measurements allow us to reach the regime of a single electron-hole pair per dot, evidenced by a monoexponential decay of the luminescence and a stop of the time-dependent shift of the emission energy. The transition energy and the radiative lifetime of the QD ground state are measured in the absence of any electric field screening effect, for a wide range of QD heights. These results are analyzed within an envelope function model for the electron and hole confinement. The effective electric field, averaged over the strain distribution in the dots, is determined to be of 9.0 +/- 0.5 MV/cm.
107 citations
TL;DR: In this article, the authors demonstrate strong light matter coupling at low and room temperature in bulk GaN microcavities with epitaxial (Al,Ga)N Bragg mirrors grown on silicon (111).
Abstract: We present experimental results demonstrating strong-light matter coupling at low and room temperature in bulk GaN microcavities with epitaxial (Al,Ga)N Bragg mirrors grown on silicon (111). At low temperature, the strong coupling of both the $A$ and $B$ excitonic features of GaN with the cavity mode is clearly resolved in the microcavity. At room temperature a Rabi energy of $50\phantom{\rule{0.3em}{0ex}}\mathrm{meV}$ is observed and well reproduced using transfer-matrix reflectivity calculations describing the interaction of both the $A$ and $B$ excitonic states with the photonic mode.
33 citations
TL;DR: In this paper, the authors demonstrate strong light-matter coupling at room temperature in a GaN microcavity using simultaneous reflectivity and photoluminescence measurements, despite the well-known dominance of GaN emission at low temperature by localized neutral donor bound excitons.
Abstract: We demonstrate strong light-matter coupling at room temperature in a GaN microcavity using simultaneous reflectivity and photoluminescence measurements. At $10\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ strong coupling is also observed in both measurements despite the well-known dominance of GaN emission at low temperature by localized neutral donor bound excitons. In addition, the strong light-matter coupling regime is studied as a function of temperature with the tuning of the polariton modes, in this case a result due to the dominant redshift of the excitonlike branch with increasing temperature.
27 citations
TL;DR: In this paper, the photoluminescence (PL) wavelength redshifts up to 1.52μm for InAs overgrown by a Ga0.85In0.15N0.012As0.988 layer.
Abstract: InAs quantum dots (QDs) overgrown by a Ga0.85In0.15NxAs1−x (0⩽x⩽0.017) layer have been realized on GaAs substrate by molecular beam epitaxy. When the nitrogen composition increases, the photoluminescence (PL) wavelength redshifts up to 1.52μm. It is shown that PL properties of InAs∕Ga0.85In0.15N0.012As0.988 QDs are improved by thermal annealing. Finally, 1.45μm PL emission with a 38.5meV full width at half maximum is obtained at room temperature.
21 citations
TL;DR: In this paper, AlGaN/GaN quantum wells and High Electron Mobility Transistors (HEMTs) have been grown by molecular beam epitaxy on Si(111) and GaN on sapphire templates.
Abstract: In the present work, AlGaN/GaN quantum wells and High Electron Mobility Transistors (HEMTs) have been grown by molecular beam epitaxy on Si(111) and GaN on sapphire templates. The optical quality and the electrical properties were studied by low temperature photoluminescence and Hall effect. These measurements attest the quality of these heterostructures and demonstrate the high on-wafer uniformity of the materials grown on 50 mm wafers, and this even for the III-nitrides grown on Silicon. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
15 citations
TL;DR: In this paper, an AlGaN/GaN HEMT was realized on silicon (001) substrate with noticeably better transport and electrical characteristics than previously reported. And the 2D electron gas formed at the interface exhibits a sheet carrier density of 8×1012 cm−2 and a Hall mobility of 1800 cm2/V ǫs at room temperature.
14 citations
TL;DR: AlGaN/GaN high electron mobility transistors have been realized on resistive Si(001) substrate in this article, where the heterostructure was grown by molecular beam epitaxy.
Abstract: AlGaN/GaN high electron mobility transistors have been realised on resistive Si(001) substrate. The heterostructure was grown by molecular beam epitaxy. The 2D electron gas formed at the AlGaN/GaN interface exhibits a sheet carrier density of 7.1×1012 cm−2 and a Hall mobility of 1500 cm2/V s at room temperature. High electron mobility transistors with a gate length of 3 µm have been processed and DC characteristics have been achieved. A maximum drain current of more than 440 mA/mm and a transconductance gm of 120 mS/mm have been obtained. These encouraging results open the way for GaN-based electronic applications on Si(001) substrates.
14 citations
TL;DR: In this paper, the influence of indium composition and quantum well thickness on the photoluminescence properties of high nitrogen content (Ga,In)(N,As)∕GaAs QWs grown by molecular beam epitaxy has been investigated in order to get an efficient emission in the 1.5-1.7μm range.
Abstract: The influence of indium composition and quantum well (QW) thickness on the photoluminescence (PL) properties of high nitrogen content (Ga,In)(N,As)∕GaAs QWs grown by molecular beam epitaxy has been investigated in order to get an efficient emission in the 1.5–1.7μm range. Strong enhancement of room-temperature PL has been observed for postgrowth annealed QWs. However, the optimum annealing temperature depends on the In composition. Taking into account the effects of thermal annealing, a high In content and a very low growth temperature appear to be the best way to obtain an efficient emission beyond 1.5μm with (Ga,In)(N,As)∕GaAs QW.
13 citations
TL;DR: In this paper, specular and non-specular X-ray reflectometry experiments have been performed on two MBE-samples elaborated with different shutter sequences at the interfaces, and the results have revealed the presence of a highly disturbed thin-layer on top of the MOVPE-made GaInAs, whose presence has been explained by Inconcentration modification during the desoxidation procedure at the surface of the InAs.
5 citations
TL;DR: In this paper, the growth by molecular beam epitaxy of AlGaN/GaN high electron mobility transistors (HEMTs) on Si(111)/SiO2/polySiC substrates is reported.
4 citations
TL;DR: In this article, AlGaN/GaN high electron mobility transistors have been grown on Silicon (111), Silicon Carbide and GaN templates on Sapphire, and both the structural and electrical properties of these layers have been studied in order to determine the impact of substrate choice on dislocation density, strain state, roughness and electron mobility.
Abstract: In this work AlGaN/GaN high electron mobility transistors have been grown on Silicon (111), Silicon Carbide and GaN templates on Sapphire. Both the structural and the electrical properties of these layers have been studied in order to determine the impact of substrate choice on dislocation density, strain state, roughness and electron mobility.
01 Jan 2006
TL;DR: Les alliages semiconducteurs a base de nitrure de gallium permettent de realiser des diodes electroluminescentes (DELs) tres performantes emettant de la lumiere blanche as mentioned in this paper.
Abstract: Les alliages semi-conducteurs a base de nitrure de gallium permettent de realiser des diodes electroluminescentes (DELs) tres performantes emettant de la lumiere blanche. Nous presentons le principe de fonctionnement de ces diodes blanches qui sont a l'origine d'une revolution annoncee dans le domaine de l'eclairage. Une approche originale de DEL blanche monolithique en cours d'etude au CRHEA/CNRS est egalement discutee.
TL;DR: In this article, self-organized quantum dots covered by low temperature (Ga,In)As layer with different thicknesses and indium contents have been grown on GaAs substrates by molecular beam epitaxy.
Abstract: InAs self-organized quantum dots covered by low temperature (Ga,In)As layer with different thicknesses and indium contents have been grown on GaAs substrates by molecular beam epitaxy The most efficient emission is obtained for islands covered by 5 nm thick Ga085In015As cap layer A strong room temperature emission at 133 µm with a linewidth as narrow as 21 meV is observed Moreover, the analysis of temperature dependent photoluminescence intensity indicates that the main quenching mechanism comes from carrier escape from the dots to the confined level of the quantum well formed by the cap layer and the wetting layer (© 2006 WILEY-VCH Verlag GmbH & Co KGaA, Weinheim)
TL;DR: In this article, the authors demonstrate strong light-matter coupling at room temperature in bulk GaN microcavities grown on silicon and demonstrate strong coupling with epitaxial distributive Bragg reflectors.
Abstract: We present experimental results demonstrating strong light-matter coupling at room temperature in bulk GaN microcavities grown on silicon(111). Simple low finesse planar microcavities show a Rabi energy as high as 60 meV at room temperature. We also demonstrate room temperature strong-coupling from a bulk GaN microcavity with epitaxial distributive Bragg reflectors (DBRs). Furthermore, for this structure at low temperature, the strong coupling of both the A and B excitonic features of GaN with the cavity mode are clearly resolved for the first time in such a microcavity. At room temperature a Rabi energy of 50 meV is observed, and well reproduced using numerical analysis describing the interaction of both the A and B excitonic states with the photonic mode.
TL;DR: In this paper, self-assembled InAs quantum dots encapsulated by GaxIn1−xNyAs1−y (GINA) have been grown on GaAs (001) substrate by solid source molecular beam epitaxy.
Abstract: Self-assembled InAs quantum dots encapsulated by GaxIn1–xNyAs1–y (GINA) have been grown on GaAs (001) substrate by solid source molecular beam epitaxy. A wavelength of up to 1.52 µm is achieved for as-grown samples with y = 1.7%. The growth temperature of the GINA cap layer and the ex-situ annealing temperature are optimized in order to get the best photoluminescence characteristics. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)