Effective mass of heavy holes in diamond-like semiconductors

Abstract

Nonparabolicity of the heavy hole band in diamond-like semiconductors, which occurs within the framework of the three band model with the perturbation from the other bands taken into account to the Lowdin prucedure, is studied. A direct dependence of nonparabolicity on the band anisotropy (caused by the different effect of γ15c and γ12c bands) and the inverse dependence on the magnitude of the spin-orbit splitting is established. A connection between the effective mass of heavy holes and their energy is obtained, which is valid for the majority of diamond-like semicondactors, except for materials with very strong nonparabolicity of the band of silicon type.