Semi-empirical tightbinding bandstructures for II–VI zincblende compounds

Abstract

We have used a modified version of the sp 3 s ∗ semi-empirical nearest-neighbor tightbinding formalism to compute the bandstructures of the II–VI zincblende compounds ZnTe, ZnSe, ZnS, and HgSe. Our scheme includes the effects of spin-orbit coupling and, in contrast to previous sp 3 s ∗ schemes which fit differences in diagonal tightbinding matrix elements to atomic energy differences, it fits every tightbinding parameter to available band structure data. The resulting parameters show that the scaling factors for the diagonal matrix elements used in previous sp 3 s ∗ calculations are approximately valid for the compounds considered. The resulting bandstructures are in reasonable agreement with published pseudopotential calculations.