Electronic Structure of Self-Organized InAs/GaAs Quantum Dots Bounded by {136} Facets

Recent experiments indicate that the shape of self-organized InAs quantum dots grown on GaAs [001] is an elongated pyramid with bounding facets corresponding to a family of four (Formula presented) planes. This structure, which possesses (Formula presented) symmetry, is quite different from square-base pyramidal or lens geometries, which have been assumed in previous electronic structure calculations for this system. In this paper, we consider theoretically the influence of the (Formula presented) shape on the electronic structure and optical properties of the quantum dots. We present a valence force-field calculation of the inhomogeneous strain and incorporate the results into an eight band (Formula presented) electronic structure calculation. The size dependence of the electronic structure is calculated and compared to experimental photoluminescence spectra. The effects of perturbations on the (Formula presented) shape are also considered. Calculations based on the (Formula presented) shape give good agreement with the observed level structure and optical polarization properties of self-organized InAs/GaAs quantum dots.