Quasiparticle self-consistentGWband structure ofβ-Ga2O3and the anisotropy of the absorption onset

Quasiparticle self-consistent GW calculations are presented for the band structure of β-Ga2O3, including a lattice polarization correction of the screened Coulomb interaction W. It is found that this correction is of the order of 0.5 eV. When an estimated zero-point motion correction is also included, the direct gap is found to be 4.8 ± 0.1 eV in good agreement with experiment. The indirect gap is found to be 0.1 eV smaller. The origin of the anisotropy of the absorption edge is interpreted in terms of selection rules and the symmetry labeling of the bands at Γ.