Quasiparticle approximation electronic structure of the Ge/Si heterojunction to correct the local-density approximation band alignments

Abstract

The core of the LDA–½ quasiparticle approximation methodology are electrostatic self-energy corrections through precise determinations of the cutoff radius which, once determined, truncates the long-ranged self-energy function originated by the procedure of removing the spurious self-energy of electrons (or holes), responsible for most of excited-states pathologies in pure LDA. Depending on the dimensionality of the system in question, one issue regarding heterostructures electronic structure calculations is how the confinement factor, which is related to the amount of self-energy to be considered in calculations, affects the band alignments. This work presents theoretical results for the Ge/Si(100) interface band offsets, and final results for valence and conduction band offsets of 0.71 eV and 0.45 eV, respectively, which are in excellent agreement with experiments.