Monte Carlo simulation of real-space electron transfer in GaAs-AlGaAs heterostructures

Abstract

The Monte Carlo method has been used to simulate electron transport in GaAs/AlGaAs heterostructures with an electric field applied parallel to the heterojunction interface. The simulations indicate that a unique physical mechanism for negative differential conductivity is provided by such layered heterostructures, which is analogous in many respects to the Gunn effect. This mechanism has been termed ’’real-space electron transfer’’ since it involves the transfer of electrons from a high-mobility GaAs region to an adjacent low-mobility AlGaAs region as the applied electric field intensity is increased. The simulations further indicate that the important details of the resulting velocity-field characteristics for these layered heterostructures can be controlled primarily through material doping densities, layer thicknesses, and the material properties of the individual layers. Thus, the phenomenon of real-space electron transfer potentially provides the ability to ’’engineer’’ those basic material properties which influence the performance of negative resistance devices.