Computational study of defect complexes in $\beta$-LiGaO$_2$ and their relation to the donor-acceptor-pair recombination

Abstract

Hybrid functional calculations are presented for defects in LiGaO$_2$ with the fraction of non-local exchange adjusted to reproduce the recently reported exciton gap of 6.0 eV. We study how the defect transition levels of the main native defects change with respect to the band edges compared to earlier calculations which assumed a smaller band gap near 5.1 eV. In addition, we consider defect complexes formed by combining the main native donor Ga$_\mathrm{Li}$ with the main acceptors, $V_\mathrm{Li}$ and Li$_\mathrm{Ga}$ antisites as function of their relative position. These results are used to tentatively identify the photoluminescence bands previous assigned to donor-acceptor-pair recombination.