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Title: Atomistic tight-binding study of electronic structure and interband optical transitions in GaBi{sub x}As{sub 1−x}/GaAs quantum wells

Large-supercell tight-binding calculations are presented for GaBi{sub x}As{sub 1−x}/GaAs single quantum wells (QWs) with Bi fractions x of 3.125% and 12.5%. Our results highlight significant distortion of the valence band states due to the alloy disorder. A large full-width-half-maximum (FWHM) is estimated in the ground state interband transition energy (≈33 meV) at 3.125% Bi, consistent with recent photovoltage measurements for similar Bi compositions. Additionally, the alloy disorder effects are predicted to become more pronounced as the QW width is increased. However, they are less strong at the higher Bi composition (12.5%) required for the design of temperature-stable lasers, with a calculated FWHM of ≈23.5 meV at x = 12.5%.
Authors:
 [1] ;  [1] ;  [2]
  1. Tyndall National Institute, Lee Maltings, Dyke Parade, Cork (Ireland)
  2. (Ireland)
Publication Date:
OSTI Identifier:
22283133
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; ABSORPTION SPECTROSCOPY; BISMUTH COMPOUNDS; CONCENTRATION RATIO; ELECTRONIC STRUCTURE; ENERGY-LEVEL TRANSITIONS; GALLIUM ARSENIDES; GROUND STATES; HETEROJUNCTIONS; LASER RADIATION; QUANTUM WELLS; VALENCE; X-RAY SPECTROSCOPY