Theory of high-field transport of holes in GaAs and InP

Abstract

Calculations of the steady-state drift velocity and impact ionization rate of holes in the valence bands of GaAs and InP are presented based on a Monte Carlo simulation with the unique inclusion of a complete band structure (derived using the $\overrightarrow{\mathrm{k}}·\overrightarrow{\mathrm{p}}$ method) and quantum effects such as collision broadening. The results are found to fit the experimental data well throughout an enormous range of applied electric fields. No appreciable anisotropy in the impact ionization rate is obtained theoretically in either material. The impact ionization rate in InP is much lower than in GaAs largely because of the greater density of states in InP and the corresponding higher hole-phonon scattering rate. A possible explanation of the difference in the ratio of electron over hole ionization rates in GaAs and InP is also presented.