Electronic structure and vertical transport in single-barrier AIN/GaN heterostructures

摘要

In this work we investigate the charge distribution and vertical electron transport through GaN/AlN/GaN single-barrier structures with different AlN thickness. The results of electrical characterization are interpreted by comparison with simulations of the electronic structure using a self-consistent Schrodinger-Poisson equation solver. Capacitive measurements confirm the formation of a two-dimensional electron gas at the bottom interface of the AlN barrier, even for barrier thickness of 2 ML. Conductive atomic force microscopy reveals that the cur-rent flow concentrates at discrete locations whose density is in the 10(7) cm(-2) range, more than one order of magnitude lower than the dislocation density in these samples.