Multistability of isolated and hydrogenated Ga–O divacancies in β−Ga2O3

The combination of an ultrawide band gap and controllable $n$-type conductivity makes monoclinic gallium sesquioxide a promising material for high-power electronics. However, this technological development will require accurate knowledge about the identity and properties of prominent deep-level defects in the material. This work explores close-associate Ga-O divacancies. Owing to the low symmetry of the crystal structure, divacancies can potentially occur in a plethora of crystallographically inequivalent configurations. Hybrid functional calculations were performed to shed light on the relative stability of different divacancy configurations, the energy barriers for transformation between them, and trends in their electrical properties.