Energy gaps, effective masses and ionicity of AlxGa1−xSb ternary semiconductor alloys

Abstract

A pseudopotential calculation of the electronic structure of Al[Formula: see text]Ga[Formula: see text]Sb ternary alloys in the zinc-blende structure has been performed. The compositional dependence of energy gaps, electron and heavy hole effective masses and ionicity of the material system of interest have been examined and discussed. Special attention has been given to the effect of the alloy disorder on the direct ([Formula: see text]–[Formula: see text]) bandgap energy. It is found that all features of interest vary monotonically with increasing the Al concentration [Formula: see text]. Besides, bandgap bowing parameters and extent of the direct-to-indirect bandgap transition have been determined. Our findings agree generally well with the data reported in the literature. Trends in ionicity are found to be consistent with the Phillips ionicity scale.