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

Journal Article · Mon Oct 13 04:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4897006· OSTI ID:22350913

Bocquel, J.; Koenraad, P. M. ^[1]; Giddings, A. D.; Prosa, T. J.; Larson, D. J. ^[2]; Mano, T. ^[3]

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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)

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.

• OSTI ID: 22350913
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 15 Vol. 105; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM COMPOUNDS
ASPECT RATIO
CARRIER MOBILITY
CATIONS
CRYSTAL GROWTH
CRYSTALLIZATION
DROPLETS
EPITAXY
ETCHING
GALLIUM ARSENIDES
QUANTITATIVE CHEMICAL ANALYSIS
QUANTUM DOTS
SCANNING TUNNELING MICROSCOPY
TOMOGRAPHY