Growth of highly dense InAs quantum dots with improved crystal quality embedded in an InGaAsSb quantum well

Abstract

We investigate the structural and optical properties of InAs quantum dots (QDs) embedded in InxGa1−xAs0.96Sb0.04 layers with different In content. Indium incorporation from 0 to 9% increases QD areal density up to 9.3 × 1010 cm−2 and decreases QD diameter and height by the reduction of the island–island interaction. The elastic strain of the InGaAsSb layers, surrounded by a GaAs matrix, increases with higher In content. Further, the increase of In content from 5 to 9% reduces the density of dislocation loops in the InGaAsSb and GaAs layers almost by half due to improvement of the InAs/InGaAsSb interface quality. The photoluminescence peak from the QDs is redshifted with increasing In content as a result of reduced strain inside the QDs.