Native defects and their complexes in spinel LiGa5O8

Recently, LiGa 5O 8 was identified as a cubic spinel type ultra-wide-bandgap semiconductor with a gap of about 5.36 eV and reported to be unintentionally p-type. Here, we present first-principles calculations of native defects and their various complexes to try to explain the occurrence of p-type doping. Although we find Li vacancies (0.74 eV above VBM) to be shallower acceptors than in LiGaO 2 (1.63 eV above VBM), and becoming slightly shallower in complexes with donors such as V O (0.58 eV above VBM) and Ga Li antisites (0.65 eV above VBM), these V Li based defects are not sufficiently shallow to explain p-type doping. The dominant defects are donors and, in equilibrium, the Fermi level would be determined by compensation between donors and acceptors and pinned deep in the gap.