Heterojunction valence-band-discontinuity dependence on face orientation

Band offsets for the (100), (110), (111), and (1{} 1{} 1{}) orientation of the GaAs-AlAs and CdTe-HgTe heterojunctions have been investigated by use of a self-consistent tight-binding method. Our results show an important face dependence for the band offsets of the CdTe-HgTe heterojunction ({}0.20 eV), although differences for the GaAs-AlAs interface are negligible. We conclude that for high-ionicity semiconductors there is a slight dependence of the charge neutrality level on the face orientation.