Vertical Electron Transport in GaN/AlGaN Heterostructures

Nonequilibrium dc and large-signal ac vertical electron transport in GaN/AlGaN heterostructures is investigated by Monte Carlo simulations.The symmetric two-barrier GaN/AlGaN heterostructures are studied.The results of simulations show that polarization charges have a profound effect on dc and large-signal ac characteristics of vertical electron transport in GaN/AlGaN heterostructures.Under certain composition, geometry and doping profile, the GaN/AlGaN heterostructures may become bipolar, i.e., the inversion layers may originate at heterointerfaces due to strong built-in electric fields, which are induced by polarization charges.