Electronic Structure and Optical Properties of Strained Type-II InAs_xSb_1-x/InAs Quantum Dots for Mid-Infrared Applications

Abstract

InSb-based self-assembled quantum dots (SAQDs) are very promising for the mid-infrared (3-5 μm) optical range. We have analysed the electronic structure and optical properties of InAsxSb1-x/InAs dots. In this paper, we present the results of the modelling of electronic structure and optical properties from photoluminescence (PL) measurement for InAsxSb1-x/InAs SAQDs, focusing on the effects of SAQD morphology and composition. In particular, we analyse the electronic structure of InAsxSb1-x/InAs SAQD of various shapes, aspect ratios and compositions. We also suggest a method of assessing the geometry and composition of InAsxSb1-x/InAs quantum dots using their optical spectra and limited microscopy information. The calculated transition energies agree well with the experimental results. The results show that the geometry of the dot can be estimated from the optical spectra if the composition is known, and vice versa.