Hybrid MBE-CBE Growth and Characterization of Al 0.48 In 0.52 As on InP(100) for avalanche photodiode applications Motivation

International audienceIn this work, we demonstrate the epitaxial growth of high quality, low strain and low background doping of Al0.48In0.52As at 500°C on Fe-doped semi-insulating InP(100) substrate by using hybrid MBE-CBE technique. The precursors that were used are: solid aluminum, solid indium, TriMethylIndium (TMIn) and thermally cracked arsine. Using Nomarski, we observed smooth surfaces for the as grown layers. High-Resolution X-ray Diffraction (HR-XRD) in the vicinity of the (004) reflexion shows a lattice mismatch in the range -137 to 127ppm. The carrier density of undoped layers, obtained by Hall measurement at room temperature, is as low as 3E+15 cm-3 which is three orders of magnitude lower than the identical layers grown by organometallics sources. Photoluminescence (PL) for Al0.48In0.52As at low temperature (LT) shows a good optical quality. The quality and purity of the alloys grown here are compatible with high performance APD for optical communication

Optical spatial solitons at the interface between two dissimilar periodic media: Theory and experiment

Discrete spatial solitons traveling along the interface between two dissimilar one-dimensional arrays of waveguides were observed for the first time. Two interface solitons were found theoretically, each one with a peak in a different boundary channel. One evolves into a soliton from a linear mode at an array separation larger than a critical separation where-as the second soliton always exhibits a power threshold. These solitons exhibited different power thresholds which depended on the characteristics of the two lattices. For excitation of single channels near and at the boundary, the evolution behavior with propagation distance indicates that the solitons peaked near and at the interface experience an attractive potential on one side of the boundary, and a repulsive one on the opposite side. The power dependence of the solitons at variable distance from the boundary was found to be quite different on opposite sides of the interface and showed evidence for soliton switching between channels with increasing input power

Optical modes at the interface between two dissimilar discrete meta-materials

We have studied theoretically and experimentally the properties of optical surface modes at the hetero-interface between two meta-materials. These meta-materials consisted of two 1D AlGaAs waveguide arrays with different band structures

Chemical composition of nanoporous layer formed by electrochemical etching of p-type GaAs

Abstract : We have performed a detailed characterization study of electrochemically etched p-type GaAs in a hydrofluoric acid-based electrolyte. The samples were investigated and characterized through cathodoluminescence (CL), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). It was found that after electrochemical etching, the porous layer showed a major decrease in the CL intensity and a change in chemical composition and in the crystalline phase. Contrary to previous reports on p-GaAs porosification, which stated that the formed layer is composed of porous GaAs, we report evidence that the porous layer is in fact mainly constituted of porous As2O3. Finally, a qualitative model is proposed to explain the porous As2O3 layer formation on p-GaAs substrate

On the Test Particle Monte-Carlo method to solve the steady state Boltzmann equation, the congruity of its results with experiments and its potential for shared memory parallelism

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Virtual Substrates Engineering for High Efficiency Multijunction Solar Cells Applications.

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Virtual Substrates Engineering for High Efficiency Multijunction Solar Cells Applications.

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Second Harmonic Generation in AlGaAs Nanowaveguides

In this paper, we investigate semiconductor nanowaveguides (i.e. ridge waveguides with core-widths narrower than 1 μm) intended to act as novel optical light sources through nonlinear wavelength/frequency conversion. In particular, numerical calculations have been performed in order to design suitable photonic devices (fabricated in the AlGaAs/GaAs platform) capable of high efficiency second harmonic generation. Particular interest has been dedicated to the effective conversion of optical signals from 1520-1600 nm (the third telecom window) down to 760-800 nm. We demonstrate that the output wavelength (resulting from modal phase-matching) can be dynamically tuned by proper adjustment of the temperature and/or geometrical parameters of the waveguides. In addition, by changing the waveguide width it is also possible to modify the device dispersion characteristics, giving the possibility to work in the region of anomalous dispersion and thus allowing for the generation of temporal solitons

Graphene-porous semiconductor nanocomposites scalable synthesis for energy applications

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Epitaxial lift-off process for Ill-V solar cells by using porous germanium for substrate re-use

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