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Photoreflectance study of growth mode in InAs–GaAs quasimonolayer single quantum wells

Authors :
Amalia Patanè
M. Geddo
Mario Capizzi
Faustino Martelli
Source :
Journal of Applied Physics. 84:3374-3377
Publication Year :
1998
Publisher :
AIP Publishing, 1998.

Abstract

Photoreflectance measurements have been performed in a number of InAs/GaAs single-quantum wells with nominal thickness L ranging from 0.6 to 2.0 ML. The InAs growth mode was investigated by analyzing the evolution, with increasing coverage, of the optical response associated with the InAs layer. For L⩽1.6 ML, the experimentally derived energies for the optical transition originating in the InAs are consistent with those evaluated in a simple square-well envelope-function scheme. The dependence of the photoreflectance line shape broadening on L is well described up to L=1.4 ML in terms of a disordered InAs/GaAs interface made by interconnected InAs and GaAs islands with a typical size of order 2 nm. For L=1.6 ML, the quantum well spectral features broaden abruptly and vanish for L=2 ML, suggesting the disappearance of the InAs 2D layer in favor of a predominant nucleation of large quantum dots.

Details

ISSN :
10897550 and 00218979
Volume :
84
Database :
OpenAIRE
Journal :
Journal of Applied Physics
Accession number :
edsair.doi...........0a950be14d6ca014082be2502b3970e8