Theoretical valence band offsets of semiconductor heterojunctions

Abstract

A theoretical model is presented to predict the valence band offsets of heterojunction semiconductors. The total valence band offsets are split into bulk and interfacial contributions. The bulk contributions are based on the tight binding approach while the localized effects at the interface are described by the bond exchange and the elastic energy due to the strained layer. We calculate the valence band offsets for various types of heterojunctions and compare that with experimental data and the results of other theoretical calculations. Our results are in good agreement with experimental data for most of the systems explored. This suggests that the present model is generic and contains the dominant physical factors operative at the interface to make it applicable to various heterojunctions.