A new semiconductor alloy material, GaAs1-xBix has been created by Metal Organic Vapor Phase Epitaxial (MOVPE) growth. A low growth temperature, such as 365°C, is required to obtain the alloy. X-ray diffraction measurements of alloy layers reveal that the diffraction patterns are satisfactory. The maximum GaBi content in the GaAsBi alloy estimated from the lattice constant is around 2%, which is consistent with that estimated from secondary ion mass spectroscopy (SIMS) measurements. In a photoluminescence (PL) measurement, a single peak spectrum is observed from 10 to 300 K. The temperature variation of the PL peak energy is as small as 0.1 meV/K.

New Semiconductor Alloy GaAs_ Bi_x Grown by Metal Organic Vapor Phase Epitaxy

Progress in the design and fabrication of ultraviolet and deep-ultraviolet group III–nitride optoelectronic devices, based on aluminum gallium nitride and boron nitride and their alloys, and the heterogeneous integration with two-dimensional and oxide-based materials is reviewed. We emphasize wide-bandgap nitride compound semiconductors (i.e., (B, Al, Ga)N) as the deep-ultraviolet materials of interest, and two-dimensional materials, namely graphene, two-dimensional boron nitride, and two-dimensional transition metal dichalcogenides, along with gallium oxide, as the hybrid integrated materials. We examine their crystallographic properties and elaborate on the challenges that hinder the realization of efficient and reliable ultraviolet and deep-ultraviolet devices. In this article we provide an overview of aluminum nitride, sapphire, and gallium oxide as platforms for deep-ultraviolet optoelectronic devices, in which we criticize the status of sapphire as a platform for efficient deep-ultraviolet devices and detail advancements in device growth and fabrication on aluminum nitride and gallium oxide substrates. A critical review of the current status of deep-ultraviolet light emission and detection materials and devices is provided.

/pdf/deep-ultraviolet-integrated-photonic-and-optoelectronic-5dq7elisbn.pdf

Deep-ultraviolet integrated photonic and optoelectronic devices: A prospect of the hybridization of group III-nitrides, III-oxides, and two-dimensional materials

Herein we investigate a (001)-oriented GaAs1−xBix/GaAs structure possessing Bi surface droplets capable of catalysing the formation of nanostructures during Bi-rich growth, through the vapourliquid-solid mechanism. Specifically, self-aligned “nanotracks” are found to exist trailing the Bi droplets on the sample surface. Through cross-sectional high-resolution transmission electron microscopy the nanotracks are revealed to in fact be elevated above surface by the formation of a subsurface planar nanowire, a structure initiated mid-way through the molecular-beam-epitaxy growth and embedded into the epilayer, via epitaxial overgrowth. Electron microscopy studies also yield the morphological, structural, and chemical properties of the nanostructures. Through a combination of Bi determination methods the compositional profile of the film is shown to be graded and inhomogeneous. Furthermore, the coherent and pure zincblende phase property of the film is detailed. Optical characterisation of features on the sample surface is carried out using polarised micro-Raman and micro-photoluminescence spectroscopies. The important light producing properties of the surface nanostructures are investigated through pump intensity-dependent micro PL measurements, whereby relatively large local inhomogeneities are revealed to exist on the epitaxial surface for important optical parameters. We conclude that such surface effects must be considered when designing and fabricating optical devices based on GaAsBi alloys.

/pdf/surface-effects-of-vapour-liquid-solid-driven-bi-surface-20ww9z8hy3.pdf

Surface effects of vapour-liquid-solid driven Bi surface droplets formed during molecular-beam-epitaxy of GaAsBi

Calculation of band structure and optical gain of type-II GaSbBi/GaAs quantum wells using 14-band k·p Hamiltonian

Effect of Sb and N resonant states on the band structure and carrier effective masses of GaAs 1-x-y N x Sb y alloys and GaAs 1-x-y N x Sb y /GaAs quantum wells calculated using k·p Hamiltonian

Influence of Bi and N related impurity states on the band structure and band offsets of GaSbBiN alloys

Hydrostatic Pressure Dependent Optoelectronic Properties of InGaAsN/GaAs Spherical Quantum Dots for Laser Diode Applications

Dependence of heavy hole exciton binding energy and the strain distribution in GaAs1−xBix/GaAs finite spherical quantum dots on Bi content in the material

Akant Sagar Sharma

Papers

Influence of Bi and N related impurity states on the band structure and band offsets of GaSbBiN alloys

Hydrostatic Pressure Dependent Optoelectronic Properties of InGaAsN/GaAs Spherical Quantum Dots for Laser Diode Applications

Dependence of heavy hole exciton binding energy and the strain distribution in GaAs1−xBix/GaAs finite spherical quantum dots on Bi content in the material

Growth of dilute quaternary alloy InPNBi and its′ characterization

Anomalous increase of sub-band gap photoluminescence from InPBi layers grown by liquid phase epitaxy