Strain distribution and electronic spectra of InAs/GaAs self-assembled dots: An eight-band study

Abstract

Strained epitaxy has been shown to produce pyramidal-shaped quantum dot structures by single-step epitaxy. In this paper we examine the strain tensor in these quantum dots using a valence force field model. We use an eight-band $\mathbf{k}\ensuremath{\cdot}\mathbf{p}$ formalism to find the electronic spectra in the highly strained dots. Results obtained for the conduction-band spectra using the effective-mass approach are shown to have serious errors. This is particularly true for excited states in the conduction band. The dependence of the electronic spectra on the quantum dot size and shape is also reported along with comparisons with published experimental results.