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A comprehensive study of the effect of in situ annealing at high growth temperature on the morphological and optical properties of self-assembled InAs/GaAs QDs

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Title A comprehensive study of the effect of in situ annealing at high growth temperature on the morphological and optical properties of self-assembled InAs/GaAs QDs
 
Creator HALDER, N
RASHMI, R
CHAKRABARTI, S
STANLEY, CR
HERRERA, M
BROWNING, ND
 
Subject molecular-beam epitaxy
quantum-dot lasers
monolayer coverage
islands
gaas
transition
density
size
 
Description We investigate the effect of in situ annealing during growth pause on the morphological and optical properties of self-assembled InAs/GaAs quantum dots (QDs). The islands were grown at different growth rates and having different monolayer coverage. The results were explained on the basis of atomic force microscopy (AFM) and photo-luminescence (PL) measurements. The studies show the occurrence of ripening-like phenomenon, observed in strained semiconductor system. Agglomeration of the self-assembled QDs takes place during dot pause leading to an equilibrium size distribution. The PL properties of the QDs are affected by the Indium desorption from the surface of the QDs during dot pause annealing at high growth temperature (520A degrees C) subsiding the effect of the narrowing of the dot size distribution with growth pause. The samples having high monolayer coverage (3.4 ML) and grown at a slower growth rate (0.032 ML s(-1)) manifested two different QD families. Among the islands the smaller are coherent defect-free in nature, whereas the larger dots are plastically relaxed and hence optically inactive. Indium desorption from the island surface during the in situ annealing and inhomogeneous morphology as the dots agglomerate during the growth pause, also affects the PL emission from these dot assemblies.
 
Publisher SPRINGER
 
Date 2011-08-29T08:23:22Z
2011-12-26T12:58:30Z
2011-12-27T05:48:33Z
2011-08-29T08:23:22Z
2011-12-26T12:58:30Z
2011-12-27T05:48:33Z
2009
 
Type Article
 
Identifier APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, 95(3), 713-720
0947-8396
http://dx.doi.org/10.1007/s00339-008-4988-y
http://dspace.library.iitb.ac.in/xmlui/handle/10054/12025
http://hdl.handle.net/10054/12025
 
Language en