We present a comprehensive, up-to-date compilation of band parameters for the technologically important III–V zinc blende and wurtzite compound semiconductors: GaAs, GaSb, GaP, GaN, AlAs, AlSb, AlP, AlN, InAs, InSb, InP, and InN, along with their ternary and quaternary alloys. Based on a review of the existing literature, complete and consistent parameter sets are given for all materials. Emphasizing the quantities required for band structure calculations, we tabulate the direct and indirect energy gaps, spin-orbit, and crystal-field splittings, alloy bowing parameters, effective masses for electrons, heavy, light, and split-off holes, Luttinger parameters, interband momentum matrix elements, and deformation potentials, including temperature and alloy-composition dependences where available. Heterostructure band offsets are also given, on an absolute scale that allows any material to be aligned relative to any other.

Band parameters for III–V compound semiconductors and their alloys

Recent advances in nonsilica fiber technology have prompted the development of suitable materials for devices operating beyond 155 mu m The III-V ternaries and quaternaries (AlGaIn)(AsSb) lattice matched to GaSb seem to be the obvious choice and have turned out to be promising candidates for high speed electronic and long wavelength photonic devices Consequently, there has been tremendous upthrust in research activities of GaSb-based systems As a matter of fact, this compound has proved to be an interesting material for both basic and applied research At present, GaSb technology is in its infancy and considerable research has to be carried out before it can be employed for large scale device fabrication This article presents an up to date comprehensive account of research carried out hitherto It explores in detail the material aspects of GaSb starting from crystal growth in bulk and epitaxial form, post growth material processing to device feasibility An overview of the lattice, electronic, transport, optical and device related properties is presented Some of the current areas of research and development have been critically reviewed and their significance for both understanding the basic physics as well as for device applications are addressed These include the role of defects and impurities on the structural, optical and electrical properties of the material, various techniques employed for surface and bulk defect passivation and their effect on the device characteristics, development of novel device structures, etc Several avenues where further work is required in order to upgrade this III-V compound for optoelectronic devices are listed It is concluded that the present day knowledge in this material system is sufficient to understand the basic properties and what should be more vigorously pursued is their implementation for device fabrication (C) 1997 American Institute of Physics

The physics and technology of gallium antimonide: An emerging optoelectronic material

Nanofabrication by electron beam lithography and its applications

Single spins trapped in self-assembled quantum dots present rich opportunities for studying their quantum mechanical properties. This Review surveys their optical properties, and the techniques for initializing, manipulating and reading out single spin qubits in these structures.

Single spins in self-assembled quantum dots

We demonstrate the growth of a low dislocation density, relaxed GaSb bulk layer on a (001) GaAs substrate. The strain energy generated by the 7.78% lattice mismatch is relieved by a periodic array of 90° misfit dislocations. The misfit array is localized at the GaSb∕GaAs interface and has a period of 5.6nm which is determined by transmission electron microscope images. No threading dislocations are visible. The misfits are identified as 90°, rather than 60°, using Burger’s circuit analysis, and are therefore not associated with generation of threading dislocations. A low dislocation density and planar growth mode is established after only 3 monolayers of GaSb deposition as revealed by reflection high-energy electron diffraction patterns. Calculations corroborate the materials characterization and indicate the strain energy generated by the 7.78% lattice mismatch is almost fully dissipated by the misfit array. The low dislocation density bulk GaSb material on GaAs enabled by this growth mode will lead to new devices, especially in the infrared regime, along with novel integration schemes.

Strain relief by periodic misfit arrays for low defect density GaSb on GaAs

High-quality homo- and hetero-epitaxial GaSb has been grown from TMGa and TMSb using atmospheric pressure metal-organic vapour-phase epitaxy (MOVPE). Unintentionally doped material was p-type. At 295 K it had a carrier concentration of around 3.0*1016 cm-3 and a corresponding Hall mobility in the range of 670 to 1000 cm2 V-1 s-1. Growth parameters were carefully correlated with surface morphology, electrical quality and photoluminescence data to establish the growth window for this material.

http://iopscience.iop.org/article/10.1088/0268-1242/3/4/007/pdf

Growth of GaSb by MOVPE

We report a study of self-assembled quantum dots (QDs) of InSb embedded in a GaSb matrix grown by metalorganic vapor phase deposition. Growth temperatures and deposition times have been optimized for maximal photoluminescence peak intensities. Photoluminescence (PL), magneto-PL, and atomic force microscopy (AFM) have been performed to estimate the size of the QDs. The quantum dots luminesce in the midinfrared at around 0.73 eV. The application of magnetic fields up to 15 T both parallel and perpendicular to the growth direction enhanced the wetting layer and bulk PL intensity and enabled an estimate to be made of the QD height and widths as 2–4 and 20–30 nm, respectively. These sizes were confirmed by AFM.

Self-assembled insb quantum dots grown on gasb : a photoluminescence, magnetoluminescence, and atomic force microscopy study

The magnetoresistance of semimetallic InAs/GaSb superlattices has been measured in parallel magnetic fields. The temperature dependence reveals for the first time the existence of a minigap at the anticrossing points between the electron and hole dispersion relations. At high magnetic fields, samples which are close to intrinsic show surprisingly large decreases in resistance of up to 70%. The magnetoresistance also depends on crystal orientation. We present a theoretical model which explains the experimental observations and estimates the minigap to be of order 7 meV.

Minigaps and novel giant negative magnetoresistance in inas/gasb semimetallic superlattices

Low-temperature photoluminescence of epitaxial GaSb grown by MOVPE from TMGa and TMSb on various substrates is studied and compared with existing results for GaSb grown by other techniques. The effects of growth conditions are considered. It is found that a growth temperature of 650 degrees C is too high, and the layers are of very poor quality, while below the optimum temperature of 600 degrees C the growth rate slows, although the optical quality appears unaffected. Investigations into the range of III/V ratios over which good quality material could be grown indicated that this factor was more critical for GaSb than for GaAs; Sb-rich conditions produced samples with poor radiative efficiency, while samples grown under Ga-rich conditions were covered in excess Ga droplets. In addition, the authors found that, in common with other growth techniques, the concentration of the native defect in GaSb could be controlled using the III/V ratio, and an excellent correlation was found between electrical results and features in the photoluminescence spectra. For layers not lattice-matched to the substrate, the spectrum is red-shifted. They surmise that this is due to differential thermal contraction of the epilayer and substrate. A homoepitaxial sample was chosen for detailed study and from the dependence of the spectra on temperature and excitation intensity, a previously observed bound exciton was confirmed and an acceptor of 15 meV binding energy was found.

N.J. Mason

Papers

Growth of GaSb by MOVPE

Self-assembled insb quantum dots grown on gasb : a photoluminescence, magnetoluminescence, and atomic force microscopy study

Minigaps and novel giant negative magnetoresistance in inas/gasb semimetallic superlattices

Photoluminescence of GaSb grown by metal-organic vapour phase epitaxy

Characterization of oxide layers on GaAs substrates