ELECTRONIC-STRUCTURE OF THE PSEUDOBINARY SEMICONDUCTOR ALLOY GAXAL1-XSB

A method for calculating the detailed electronic properties of the pse udobinary semiconductor alloy GaxAl1-xSb is presented. The technique b egins with realistic band structures obtained for the constituent comp ounds by fitting the band gap symmetry point energies to experimental data within the pseudopotential scheme. Then the virtual crystal appro ximation, which incorporates compositional disorder as an effective po tential, is used to calculate the alloy band structures and charge den sities. A detailed comparison between the theoretical predictions and experimental data demonstrates the quantitative nature of the method. The bowing parameters for the Gamma, X and L gaps and the direct-to-in direct band gap cross-over concentrations are in good agreement with t he experimental results.