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Title: GaSb quantum rings in GaAs/Al{sub x}Ga{sub 1−x}As quantum wells

We report the results of continuous and time-resolved photoluminescence measurements on type-II GaSb quantum rings embedded within GaAs/Al{sub x}Ga{sub 1−x}As quantum wells. A range of samples were grown with different well widths, compensation-doping concentrations within the wells, and number of quantum-ring layers. We find that each of these variants have no discernible effect on the radiative recombination, except for the very narrowest (5 nm) quantum well. In contrast, single-particle numerical simulations of the sample predict changes in photoluminescence energy of up to 200 meV. This remarkable difference is explained by the strong Coulomb binding of electrons to rings that are multiply charged with holes. The resilience of the emission to compensation doping indicates that multiple hole occupancy of the quantum rings is required for efficient carrier recombination, regardless of whether these holes come from doping or excitation.
Authors:
; ; ;  [1] ;  [2]
  1. Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)
  2. Department of Chemistry, Lancaster University, Lancaster LA1 4YB (United Kingdom)
Publication Date:
OSTI Identifier:
22494944
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 119; Journal Issue: 4; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION SPECTROSCOPY; GALLIUM ANTIMONIDES; GALLIUM ARSENIDES; HOLES; PHOTOLUMINESCENCE; QUANTUM WELLS; TIME RESOLUTION; X-RAY SPECTROSCOPY