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Title: Composition profiling of GaAs/AlGaAs quantum dots grown by droplet epitaxy

Droplet epitaxy (DE) is a growth method which can create III-V quantum dots (QDs) whose optoelectronic properties can be accurately controlled through the crystallisation conditions. In this work, GaAs/AlGaAs DE-QDs have been analyzed with the complimentary techniques of cross-sectional scanning tunneling microscopy and atom probe tomography. Structural details and a quantitative chemical analysis of QDs of different sizes are obtained. Most QDs were found to be pure GaAs, while a small proportion exhibited high intermixing caused by a local etching process. Large QDs with a high aspect ratio were observed to have an Al-rich crown above the GaAs QD. This structure is attributed to differences in mobility of the cations during the capping phase of the DE growth.
Authors:
;  [1] ; ; ;  [2] ;  [3]
  1. Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)
  2. CAMECA Instruments, Inc., 5500 Nobel Drive, Madison, Wisconsin 53711 (United States)
  3. National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)
Publication Date:
OSTI Identifier:
22350913
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 15; 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; 36 MATERIALS SCIENCE; ALUMINIUM COMPOUNDS; ASPECT RATIO; CARRIER MOBILITY; CATIONS; CRYSTAL GROWTH; CRYSTALLIZATION; DROPLETS; EPITAXY; ETCHING; GALLIUM ARSENIDES; QUANTITATIVE CHEMICAL ANALYSIS; QUANTUM DOTS; SCANNING TUNNELING MICROSCOPY; TOMOGRAPHY