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Article
Open AccessAl5+αSi5+δN12, a new Nitride compound
The family of III-Nitride semiconductors has been under intensive research for almost 30 years and has revolutionized lighting applications at the dawn of the 21st century. However, besides the developments an...
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Article
Open AccessIntentional polarity conversion of AlN epitaxial layers by oxygen
Nitride materials (AlN, GaN, InN and their alloys) are commonly used in optoelectronics, high-power and high-frequency electronics. Polarity is the essential characteristic of these materials: when grown along...
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Article
Correlation Between the AlN Buffer Layer Thickness and the GaN Polarity in GaN/AlN/Si(111) Grown by MBE
In this work it is shown that thin AlN buffer layers cause N-polarity GaN epilayers, with a high inversion domains density. When the AlN thickness increases, the polarity of the epilayer changes to Ga. The use...
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Article
Open AccessFiltering of Defects in Semipolar (11−22) GaN Using 2-Steps Lateral Epitaxial Overgrowth
Good-quality (11−22) semipolar GaN sample was obtained using epitaxial lateral overgrowth. The growth conditions were chosen to enhance the growth rate along the [0001] inclined direction. Thus, the coalescenc...
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Article
Symmetry and optical properties of wurtzite nanostructures with the c axis in the layer plane
In wurtzite-based quantum wells and superlattices with the c axis parallel to the layer plane, this plane is parallel either to a symmetry plane of the wurtzite lattice (type I structures, the 〈11 ...
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Chapter and Conference Paper
Structural and morphological characterization of GaN/AlGaN quantum dots by transmission electron microscopy
In recent years much attention has been devoted to GaN quantum dots (QDs) due to their potential application as light emitting diodes and lasers diodes operating in the ultra-violet range. QDs allow carriers l...
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Chapter and Conference Paper
Contribution of low tension ion-milling to heterostructural semiconductors preparation
Specimens of superior quality are required for quantitative Transmission Electron Microscopy. The classical preparation of heterostructural semiconductors includes stages of mechanical polishing followed by io...
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Chapter and Conference Paper
STEM investigations of (In,Ga)N/GaN quantum wells
Nanostructures of III-N semiconductors have a great commercial potential due to their optoelectronic properties. The structural and chemical characteristics of such structures determine the performance of the ...
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Article
Growth and characterization of A-plane ZnO and ZnCoO based heterostructures
Non polar ZnO and (Zn, Co)O layers were successfully grown on (11̄02) sapphire (R-plane sapphire). The growth process was shown to directly influence the surface morphology as well as the strain state in (112̄...
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Article
X-ray and transmission electron microscopy characterization of twinned CdO thin films grown on a-plane sapphire by metalorganic vapour phase epitaxy
In the frame of studying II–VI oxides of interest in optoelectronic technologies, the structural properties of CdO films grown by metalorganic vapour phase epitaxy on a-plane sapphire substrates have been anal...
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Chapter and Conference Paper
Strain relaxation in (Al,Ga)N/GaN heterostructures
Strain relaxation mechanisms in metal-organic vapour phase epitaxy grown (Al,Ga)N/GaN heterostructures are presented. Relaxation first occurs through a 2D–3D transition. For pure AlN, misfit a-type dislocations a...
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Article
Molecular beam epitaxy of ZnxBe1−xSe: Influence of the substrate nature and epilayer properties
We have studied the heteroepitaxial growth of ZnxBe1−xSe onto Si, GaAs and GaP substrates. By comparing the growth on these different substrates, we showed that lattice-matching is not a sufficient condition to a...
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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
Mg-enhanced lateral overgrowth of GaN on patterned GaN/sapphire substrate by selective Metal Organic Vapor Phase Epitaxy
Selective and lateral overgrowth by Metal Organics Vapour Phase Epitaxy (MOVPE) was carried out until coalescence to produce smooth and optically flat thick GaN layers. A GaN epitaxial layer is first grown usi...
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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...
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Article
Plan-view microstructures of Co/Ru bilayers
Plan-view microstructures of two Co/Ru bilayers with a composition of [Co12ÅRu45Å]2 and [Co40ÅRu35Å]2 have been studied by conventional and high resolution electron microscopy. Large differences in electron diffr...
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Article
Kinetics of SRO and LRO in FeAl Alloys with A2 and DO3 Structures
The kinetics of short and long-range ordering in FeA1x alloys have been investigated using resistometry. The results were obtained in the A2 solid solution (x = 0.10 and 0.17), in the DO3 ordered phase (x = 0.23,...
