Band Offsets at Semiconductor-Oxide Interfaces from Hybrid Density Functional Calculations

Alkauskas, Audrius; Broqvist, Peter; Devynck, Fabien; Pasquarello, Alfredo

Band Offsets at Semiconductor-Oxide Interfaces from Hybrid Density Functional Calculations

Authors

Description

Band offsets at semiconductor-oxide interfaces are determined through a scheme based on hybrid density functionals, which incorporate a fraction $α$ of Hartree-Fock exchange. For each bulk component, the fraction $α$ is tuned to reproduce the experimental band gap, and the conduction and valence band edges are then located with respect to a reference level. The lineup of the bulk reference levels is determined through an interface calculation, and shown to be almost independent of the fraction $α$. Application of this scheme to the Si-SiO$_2$, SiC-SiO$_2$, and Si-HfO$_2$ interfaces yields excellent agreement with experiment.
4 pages, 4 figures