The effect of electrostatic interactions on hot electron transport in n-GaAs

Abstract

Hot electron transport in bulk n-GaAs is investigated in a three dimensional numerical simulation. An emphasis is placed on understanding the effect of the electrostatic interaction and, in particular, that of the ionized impurity scattering on drift velocity vs electric field characteristics. In order to account for the spatial correlations between electrons and scattering centers, the numerical model combines molecular dynamics and Monte Carlo techniques. A major result is that the impurities enhance the drift velocity of hot electrons. This emphasizes the inappropriateness of the concept of a phenomenological mean free flight time when the interaction potential is long range. An explanation of the effect is proposed which applies to a general multi-valley semiconductor; and the model is compared to the traditional Brooks-Herring treatment of electron-ionized impurity scattering.