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Title: Effect of spacer layer thickness on structural and optical properties of multi-stack InAs/GaAsSb quantum dots

The structural and optical properties of ten-stack InAs/GaAsSb quantum dots (QDs) with different spacer layer thicknesses (d{sub s} = 2, 5, 10, and 15 nm) are reported. X-ray diffraction analysis reveals that the strain relaxation of the GaAsSb spacers increases linearly from 0% to 67% with larger d{sub s} due to higher elastic stress between the spacer and GaAs matrix. In addition, the dislocation density in the spacers with d{sub s} = 10 nm is lowest as a result of reduced residual strain. The photoluminescence peak energy from the QDs does not change monotonically with increasing d{sub s} due to the competing effects of decreased compressive strain and weak electronic coupling of stacked QD layers. The QD structure with d{sub s} = 10 nm is demonstrated to have improved luminescence properties and higher carrier thermal stability.
Authors:
; ;  [1] ; ;  [2]
  1. School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States)
  2. Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States)
Publication Date:
OSTI Identifier:
22485975
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CARRIERS; DISLOCATIONS; GALLIUM ARSENIDES; INDIUM ARSENIDES; LAYERS; OPTICAL PROPERTIES; PHOTOLUMINESCENCE; QUANTUM DOTS; STRAINS; STRESSES; THICKNESS; X-RAY DIFFRACTION