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Title: Height stabilization of GaSb/GaAs quantum dots by Al-rich capping

GaSb quantum dots (QDs) in a GaAs matrix are investigated with cross-sectional scanning tunneling microscopy (X-STM) and photoluminescence (PL). We observe that Al-rich capping materials prevent destabilization of the nanostructures during the capping stage of the molecular beam epitaxy (MBE) growth process and thus preserves the QD height. However, the strain induced by the absence of destabilization causes many structural defects to appear around the preserved QDs. These defects originate from misfit dislocations near the GaSb/GaAs interface and extend into the capping layer as stacking faults. The lack of a red shift in the QD PL suggests that the preserved dots do not contribute to the emission spectra. We suggest that a better control over the emission wavelength and an increase of the PL intensity is attainable by growing smaller QDs with an Al-rich overgrowth.
Authors:
;  [1] ; ; ;  [2] ; ;  [3]
  1. Department of Applied Physics, Eindhoven University of Technology, Den Dolech 2, 5612 AZ Eindhoven (Netherlands)
  2. Department of Material Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)
  3. Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)
Publication Date:
OSTI Identifier:
22303575
Resource Type:
Journal Article
Resource Relation:
Journal Name: APL Materials; Journal Volume: 2; Journal Issue: 9; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; CONTROL; DISLOCATIONS; EMISSION SPECTRA; GALLIUM ANTIMONIDES; GALLIUM ARSENIDES; INTERFACES; MOLECULAR BEAM EPITAXY; PHOTOLUMINESCENCE; QUANTUM DOTS; SCANNING TUNNELING MICROSCOPY; STABILIZATION; WAVELENGTHS