First principles modeling of high field transport in wide-band-gap materials

Abstract

In the present work, we have theoretically investigated the electronic and transport properties of three wide-band-gap materials, ZnS, SrS, and GaN, using full-band ensemble Monte Carlo (EMC) simulation. We show a suppression of the hole impact ionization rate for ZnS and SrS in particular, and GaN to a lesser extent, due to the narrowness of the upper valence bands. The resulting impact ionization coefficient for electrons in ZnS simulated using the EMC with microscopically calculated phonon scattering rates is in good agreement with the re-interpreted data of Thompson and Allen (J. Phys. C: Solid State Phys. 20 (1987) L499).