First Principle Self-Consistent Pseudopotential Calculation on the Electronic Structure of (InAs)1(GaAs)1 Superlattice

Abstract

The band structure of the (InAs)1(GaAs)1 strained superlattice is calculated by the self-consistent pseudopotential method. The results show that the (InAs)1(GaAs)1 is a direct-gap superlattice. With the local density approximation, the band gap calculated with the room-temperature lattice constants is 0.43eV, and the corrected value is 0.91eV, in agreement with experimental results. Because of the lattice mismatch between InAs and GaAs layers, the three-fold degenerate energy level at the top of valence band splits into two levels with a spacing of 0.29eV. The splitting of energy level is also estimated and explained using the effective-mass theory.