Interface roughness scattering considering the electrical field fluctuation in undoped AlxGa1−xN/GaN heterostructures

Abstract

The roughness existing in the interface between the AlxGa1−xN barrier and the GaN well gives rise to two events: the thickness fluctuation of the GaN well and the AlxGa1−xN barrier. The former results in displacement of the electron and the latter leads to fluctuation of the electrical field in the well. The mobility of two-dimensional electron gas limited by the interface roughness scattering was calculated considering the two phenomena in undoped AlxGa1−xN/GaN heterostructures. We found that the fluctuation of the electrical field caused the reduction of mobility at small barrier thickness or low sheet carrier concentrations.