Optical properties of InSb layers confined by InP

Abstract

The photoluminescence properties of InSb submonolayers and dots are presented. When the amount of InSb deposit on InP is less than 1 ML the growth mode remains two dimensional, while for greater amounts three-dimensional quantum dots are formed. Within the two-dimensional growth mode range the energy of the InSb-related transition decreases as we increase the amount of InSb deposited within the limits of said range. No InSb absorption features have been detected. The observed photoluminescence is interpreted as a recombination of electrons in the InP layers with holes in the InSb layers. We estimate a valence-band offset of 1.525 eV, similar to the predictions of the solid-model theory (1.600 eV). In the samples with InSb dots an InSb related transition has been observed, which is attributed to the wetting layer.