Quasiparticle calculations of band offsets at AlN-GaN interfaces

摘要

A first-principle quasiparticle theory in the GW approximation is used to compute valence and conduction band offsets, VBO and CBO, respectively, for hexagonal and cubic AIN-GaN interfaces. We find type I band offsets that depend on the in-plane lattice constant of the heterostructure, ranging from VBO = 1.3 eV and CBO = 1.5 eV for the in-plane lattice constant of a 6H-SiC (0001) substrate to VBO = 0.8 eV and CBO = 1.8 eV for the in-plane lattice constant of a GaN (0001) substrate. This sensitivity may explain the range of experimental results for systems whose in-plane lattice constants could not be directly measured. (C) 2002 Published by Elsevier Science Ltd. References: 28