Heterojunction band offsets and effective masses in III-V quaternary alloys

Abstract

Estimates of valence-band and conduction-band offsets for lattice-matched and pseudomorphic strained heterostructures of six technologically important III-V quaternary alloys are presented. Valence-band offsets are obtained via interpolation of the theory-based results of Van de Walle's 'model-solid' approach for the binary constituents. Estimates for band gap differences are obtained via interpolation of the experimental band gap energies of the ternary constituents. Adding the valence-band offset and band gap difference gives an estimate of the conduction-band offset. Band-edge effective masses at Gamma are determined from a linear interpolation of the effective masses of the binary constituents, obtained from self-consistent ab initio band structure calculations. Results are shown to agree well with the outcome of experiments.