Related papers: Atomistic tight-binding study of electronic struct…
Bismide semiconductor materials and heterostructures are considered a promising candidate for the design and implementation of photonic, thermoelectric, photovoltaic, and spintronic devices. This work presents a detailed theoretical study…
The incorporation of bismuth (Bi) in GaAs results in a large reduction of the band gap energy (E$_g$) accompanied with a large increase in the spin-orbit splitting energy ($\bigtriangleup_{SO}$), leading to the condition that…
We perform a systematic theoretical analysis of the nature and importance of alloy disorder effects on the electronic and optical properties of GaN$_{y}$As$_{1-x-y}$Bi$_{x}$ alloys and quantum wells (QWs), using large-scale atomistic…
Recently, there has been tremendous research interest in novel bismide semiconductor materials (such as GaBi$_x$As$_{1-x}$) for wavelength-engineered, low-loss optoelectronic devices. We report a first study of the quantum confined Stark…
We develop an atomistic, nearest-neighbor sp3s* tight-binding Hamiltonian to investigate the electronic structure of dilute bismide alloys of GaP and GaAs. Using this model we calculate that the incorporation of dilute concentrations of Bi…
We present a theoretical analysis and optimisation of the properties and performance of mid-infrared semiconductor lasers based on the dilute bismide alloy In$_{x}$Ga$_{1-x}$As$_{1-y}$Bi$_{y}$, grown on conventional (001) InP substrates.…
We observed room-temperature intersubband transitions at 1.26 microns in n-doped type-II In$_{0.3}$Ga$_{0.7}$As/AlAs strained quantum wells. An improved tight-binding model was used to optimize the structure parameters in order to obtain…
Dilute nitride bismide GaNBiAs is a potential semiconductor alloy for near- and mid-infrared applications, particularly in 1.55 $\mu$m optical communication systems. Incorporating dilute amounts of Bismuth (Bi) into GaAs reduces the…
By selective doping (Be) of the well and barrier regions of p-GaAs/AlGaAs structures we have realized the situation where the upper Hubbard band (A+ centers) has been occupied by holes in the equilibrium. We studied temperature behavior of…
We report an experimental investigation of fractional quantum Hall effect (FQHE) at the even-denominator Landau level filling factor $\nu$ = 1/2 in very high quality wide GaAs quantum wells, and at very high magnetic fields up to 45 T. The…
We analyse the optical properties of InAs$_{1-x}$Sb$_{x}$/Al$_{y}$In$_{1-y}$As quantum wells (QWs) grown by molecular beam epitaxy on relaxed Al$_{y}$In$_{1-y}$As metamorphic buffer layers (MBLs) using GaAs substrates. The use of…
Using spectroscopic ellipsometry measurements on GaP$_{1-x}$Bi$_{x}$/GaP epitaxial layers up to $x = 3.7$% we observe a giant bowing of the direct band gap ($E_{g}^{\Gamma}$) and valence band spin-orbit splitting energy…
We analyze and present applications of a recently proposed empirical tight-binding scheme for investigating the effects of alloy disorder on various electronic and optical properties of semiconductor alloys, such as the band gap variation,…
Incorporation of bismuth (Bi) in dilute quantities in (In)GaAs has been shown to lead to unique electronic properties that can in principle be exploited for the design of high efficiency telecomm lasers. This motivates the development of…
Significant efficiency droop is a major concern for light-emitting diodes and laser diodes operating at high current density. Recent study has suggested that heavily Bi-alloyed GaAs can decrease the non-radiative Auger recombination and…
We provide theoretical consideration of intersubband transitions designed in the ultrawide bandgap Aluminum Gallium Oxide ((AlxGa1-x)2O3)/Gallium Oxide (Ga2O3)) quantum well system. Conventional material systems have matured into successful…
InGaAs/GaAsBi/InGaAs quantum wells (QWs) were grown on GaAs substrates by gas source molecular beam epitaxy for realizing the type II band-edge line-up. Both type I and type II transitions were observed in the Bi containing W QWs and the…
The electronic structure of bulk GaAs$_{1-x}$Bi$_x$ systems for different atomic configurations and Bi concentrations is calculated using density functional theory. The results show a Bi-induced splitting between the light-hole and…
We have studied the In$_{x}$Ga$_{1-x}$As/In$_{y}$Al$_{1-y}$As (001) interface using first-principles ab-initio pseudopotential calculations, focusing on the effects of alloy composition and strain state on the electronic properties. In…
A design strategy for achieving broadband optical gain in GaSb-based semiconductor amplifiers operating beyond 2 \mu m is presented. By employing asymmetric GaInSb/AlGaAsSb quantum wells (QWs) of varying thicknesses, a flat and wide gain…