First-principle self-consistent pseudopotential calculation of the electronic structures of short-period (GaAs) m (AlAs) n superlattices

Abstract

With the local density approximation, the band structures of the short-period (GaAs)1(AlAs)1 and (GaAs)2(AlAs)1 superlattices are calculated by using the first-principle self-consistent pseudopotential method. The results show that the (GaAs)1(AlAs)1 superlattice is an indirect semiconductor, and the lowest conduction band state is at point in the Brillouin zone; the (GaAs)2(AlAs)1 superlattice is a direct semiconductor and the lowest conduction band state is at point . The squared matrix elements of transition are calculated. The pressure coefficients of energy gaps of the (GaAs)1(AlAs)1 and (GaAs)2(AlAs)1 superlattices are calculated and compared with those obtained by hydrostatic pressure experiments.