Intervalley Gamma -X deformation potentials for top valence bands in III-V zincblende semiconductors by ab initio pseudopotential calculations

Abstract

The authors have calculated Gamma -X hole-phonon scattering matrix elements for the top valence bands in nine III-V zincblende semiconductors AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs and InSb, by ab initio pseudopotential calculations. At the same time, the authors have calculated the eigenfrequencies and eigenvectors of transverse acoustic (TA) and optic (TO) phonons at X in these materials, which agree very well with the available experimental results. They have evaluated the Gamma -X intervalley deformation potentials (IVDPs) for the longitudinal phonons, and transverse phonons, respectively. The IVDPs for the TAX phonon are very small, as expected from symmetry. The IVDPs for the TOX phonon do not vary appreciably from one semiconductor to another, averaging about 5 eV AA-1. IVDPs for the longitudinal phonon with X1 symmetry are generally larger than those of X3 symmetry. This is due to more screening to the long-range electron-phonon interaction for the X3 phonon by electron redistribution, resulting in smaller IVDPs.