Effects of Nonparabolicity on Non-Ohmic Transport in InSb and InAs

Abstract

Hot-electron distribution functions, occupation densities, and drift velocities are calculated for InAs and InSb at room temperature, on the assumption that there are polar-optical-phonon interactions only. Exact energy-momentum dispersion and wave functions are taken into account. The distribution function and occupation density are compared with calculations based on an electron-temperature model in parabolic bands. These calculations give essentially the same result for the average energy prior to collective breakdown, but a rather different shape for the distribution function. The drift velocity, as calculated here, remains a linear function of the field up to fields well above avalanche breakdown. This behavior seems to be confirmed by experiment.