Monte Carlo studies of nonequilibrium phonon effects in polar semiconductors and quantum wells. II. Non-Ohmic transport in n-type gallium arsenide

Effects of LO-phonon disturbances on the transient and steady-state high"dc-field response of n-type gallium arsenide are studied by implementing the simulation of nonequilibrium phonon distributions into the conventional Monte Carlo algorithms for hot-carrier transport in semiconductors. Strong LO-phonon amplification is found for the whole range of fields, carrier densities, and temperatures of interest. At room temperature the phonon disturbances lead to enhancements of up to 20% of the steady-state velocity at low fields and to reductions of up to 10% for fields around and above the maximum of the velocity-field characteristics. However, detailed phase-space restrictions for LO-phonon reabsorption prevent a noticeable interference of the phonon buildup with the transient velocity overshoot.