Quasiparticle band offsets of semiconductor heterojunctions from a generalized marker method

We propose an approach to reliably calculate band offsets at heterointerfaces. It is based on standard density-functional theory, but overcomes the band-gap problem by including quasiparticle effects at the level of GW theory. Quasiparticle corrections are extracted from a heterojunction superlattice by translating the experimental concept of marker levels into a theoretical approach. The proposed scheme allows one to exploit the robust prediction of relative band positions within GW and therefore does not rely on the transferability of absolute GW corrections for the respective bulk materials. For zinc-blende GaN/AlN (001), we obtain a natural band offset of 0.55 eV, compared to 0.39 eV at the local-density approximation level.