Three-dimensional electronic properties of multiple vertically stacked InAs∕GaAs self-assembled quantum dots

Abstract

The microstructural properties and the shape of an InAs∕GaAs array grown by molecular beam epitaxy were studied using transmission electron microscopy (TEM) measurements, and the interband transitions were investigated by using temperature-dependent photoluminescence (PL) measurements. The shape of the InAs quantum dots (QDs) on the basis of the cross-sectional bright-field TEM image was modeled to be a convex-plane lens. The electronic subband energies and the wave functions were numerically calculated by using a three-dimensional finite-difference method, taking into account strain effects. The excitonic peaks corresponding to interband transitions from the ground electronic subband to the ground heavy-hole band (E1-HH1) in the multiple-stacked QDs, as determined from the PL spectra, were in reasonable agreement with the (E1-HH1) interband transition energies obtained from the results of the numerical calculations.