ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The microstructure and strain characteristics of self-assembled InAs/GaAs quantum dots(QDs) were studied by using transmission electron microscopy. Compressive strain was induced touncapped QDs from GaAs substrate and the misfit strain largely increased after the deposition ofGaAs cap layer. Tensile strain outside QD was extended along the vertical growth direction; up to 15nm above the wetting layer. Vertically nonaligned and aligned stacked QDs were grown by adjustingthe thickness of GaAs spacer layers. The QDs with a lens-shaped morphology were formed in theearly stage of growth, and their apex was flattened by the out-diffusion of In atoms upon GaAscapping. However, aligned QDs maintained their lens-shaped structure with round apex after capping.It is believed that their apex did not flatten because the chemical potential gradient of In was relativelylow due to the adjacent InAs QD layers
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.26-28.1207.pdf
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