Two-valley hydrodynamical models for electron transport in gallium arsenide: Simulation of Gunn oscillations

To accurately describe non-stationary carrier transport in GaAs devices, it is necessary to use Monte Carlo methods or hydrodynamical (or energy transport) models which incorporate population transfer between valleys. We present here simulations of Gunn oscillations in a GaAs diode based on two-valley hydrodynamical models: the classic Blotekjaer model and two recently developed moment expansion models. Scattering parameters within the models are obtained from homogeneous Monte Carlo simulations, and these are compared against expressions in the literature. Comparisons are made between our hydrodynamical results, existing work, and direct Monte Carlo simulations of the oscillator device.