Computer simulation of transferred electron devices using the displaced Maxwellian approach

Computer simulations of GaAs transferred electron devices have been performed by solving the time- and space-dependent Boltzmann equation and assuming displaced Maxwellian distributions for the two conduction band valleys. Since this model includes particle, momentum, and energy relaxation (as distinct from models using instantaneous velocity field dependence) and retains the spatial dependence (as distinct from uniform field models) it is particularly well suited for studying cases that are characterized by a strong x-dependence of electron temperature. Short devices as well as long ones operating at very high frequencies have been studied extensively, since these devices were thought and, in fact, have been found to be strongly affected by nonuniform energy relaxation due to contacts, domains, and other types of space charge. The results have been compared with experimental findings and with theoretical results computed by others.