Ensemble Monte Carlo study of electron transport in degenerate bulk GaAs

A theoretical investigation is presented of the effect of ionized impurity scattering, electron-electron interaction, and degeneracy, both separately and collectively, on the bulk steady-state transport properties of degenerate GaAs. The calculations are performed using an ensemble Monte Carlo simulation that includes an analytic nonparabolic formulation of the three principal valleys in the conduction band and all of the important phonon scattering mechanisms. It is found that the overall velocity-field characteristic is determined primarily by the action of electron-plasmon scattering at high electric fields (near the intervalley threshold field). At lower fields, below which the electrons are not heated to the threshold energy for plasmon emission, ionized impurity scattering is the most dominant mechanism. In addition the effects of degeneracy are also important throughout. Only the short-range electron-electron interaction has little effect on the velocity-field curve owing to the fact that it does not alter the net momentum or energy of the electron gas in steady-state bulk material.