13 Result(s)
within
M Leroux
Characterization and Evaluation of Materials
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Article
Photoluminescence excitation spectroscopy of GaN thin layers as a function of temperature
We report on photoluminescence and photoluminescence excitation experiments performed on hexagonal GaN layers grown on a Sapphire substrate. Information about extrinsic and intrinsic optical properties have be...
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Article
p-do** of GaN by MOVPE
Mg has been widely used as p-do** species despite its intrinsic difficulties. It is nowadays well established that during the growth process of Mg doped GaN, atomic H is generated from the decomposition of NH3 ...
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Article
Temperature behaviour of the yellow emission in GaN
Even in good quality undoped GaN samples, as assessed by the intense excitonic emission, the yellow band is present. This band has been attributed either to a shallow donor to deep double donor pair recombinat...
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Article
Tunnel radiation in the luminescence spectra of GaN-based heterostructures
Tunnel effects in luminescence spectra and electrical properties of LEDs based on InGaN/GaN-heterostructures made by different technological groups were studied. The tunnel radiation in a spectral region of 1....
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Article
Room temperature Strong coupling in low finesse GaN microcavities
We present experimental results demonstrating strong-light matter coupling at low and room temperature in bulk GaN microcavities. Angle dependent reflectivity measurements demonstrate strong-coupling with a Ra...
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Advances in the Realisation of GaN-Based Microcavities: Towards Strong Coupling at Room Temperature
In a recent paper [Phys. Rev. B 68, 153313 (2003)], we reported the first experimental observation of the strong coupling regime in a GaN-based microcavity. The λ/2 GaN optical cavity was grown by molecular be...
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Analysis of the Visible and UV Electroluminescence in Homojunction GaN LED’s
The electrical and electroluminescent properties of MOVPE GaN p-n homojunctions have been analyzed as a function of temperature and bias. Electroluminescence is observed for V>3 V under dc and ac conditions. T...
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Article
Effect of V/III Ratio on the Properties of GaN Layers Grown by Molecular Beam Epitaxy Using NH3
Ammonia as nitrogen precursor has been used to grow III-V nitrides by molecular beam epitaxy (MBE) on c-plane sapphire substrates. The efficiency of NH3 has been evaluated allowing the determination of the actual...
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Article
Comparative Study of Gan Movpe Growth Processes Using Two Different “Surface Preparation-Carrier Gas” Combinations
The growth modes and resulting microstructures of GaN films grown by Metalorganic Vapor Phase Epitaxy (MOVPE) on (0001) sapphire with either a simple nitridation of the surface and N2 as carrier gas or with a tre...
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Article
Si and Mg Doped GaN Layers Grown by Gas Source Molecular Beam Epitaxy Using Ammonia
The growth of GaN layers was carried out on c-plane sapphire substrates by molecular beam epitaxy (MBE) using NH3. Undoped GaN layers were grown at 830°C with growth rates larger than 1 μm/h. Optical properties a...
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Article
Characterization of Near Edge Optical Transitions in Undoped and Doped GaN/Sapphire Grown by MOVPE, HVPE, and GSMBE
We report a comparative study by luminescence and reflectivity of GaN grown on sapphire by MOVPE, HVPE and GSMBE. Whatever the growth technique, undoped GaN shows well resolved reflectivity spectra, allowing h...
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Article
Luminescence and Reflectivity of GaN/sapphire grown by MOVPE, GSMBE and HVPE
This work presents an optical characterization by luminescence and reflectivity of GaN layers grown on sapphire using MOVPE, HVPE and GSMBE. Well resolved optical spectra are obtained for each growth technique...
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Article
Effect of the Nitridation of the Sapphire (0001) Substrate on the GaN Growth
The analysis of the sapphire surface nitridation by in situ reflection high-energy electron diffraction evidences the formation of a relaxed AIN layer. Its role on the early stage of the GaN growth is investigate...
