A deterministic study of hot phonon effects in a 2D electron gas channel formed at an AlGaN/GaN heterointerface

Abstract

We investigate the hot phonon effects on the transport properties of a two-dimensional electron gas formed in an AlGaN/GaN heterostructure. For this purpose, we use a deterministic numerical scheme to solve the coupled system of Boltzmann transport equations. The envelope wave functions of the confined carriers are self-consistently calculated from the Schrödinger-Poisson system. The simulation results show that the electron drift velocity is reduced by hot phonons for moderate and high electric fields, but become enhanced for low fields. This interesting behavior is elucidated by virtue of the energy balance equation using an analytic electron temperature model. We find good agreement to experimental data when hot phonon and degeneracy effects are taken into account.