Journal
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
Volume 26, Issue 1-4, Pages 236-240Publisher
ELSEVIER
DOI: 10.1016/j.physe.2004.08.104
Keywords
X-STM; semiconducting III-V materials; relaxation; strain; molecular beam epitaxy; quantum dots
Ask authors/readers for more resources
We have used cross-sectional scanning-tunneling microscopy (X-STM) to compare the formation of self-assembled InAs quantum dots (QDs) and wetting layers on AlAs (100) and GaAs (100) surfaces. On AlAs we find a larger QD density and smaller QD size than for QDs grown on GaAs under the same growth conditions (500degreesC substrate temperature and 1.9 ML indium deposition). The QDs grown on GaAs show both a normal and a lateral gradient in the indium distribution whereas the QDs grown on AlAs show only a normal gradient. The wetting layers on GaAs and AlAs do not show significant differences in their composition profiles. We suggest that the segregation of the wetting layer is mainly strain-driven, whereas the formation of the QDs is also determined by growth kinetics. We have determined the indium composition of the QDs by fitting it to the measured outward relaxation and lattice constant profile of the cleaved surface using a three-dimensional finite element calculation based on elasticity theory. (C) 2004 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available