Ab-Initio Calculations of Oxygen Vacancy in Ga₂O₃ Crystals

Gallium oxide β-Ga₂O₃ is an important wide-band gap semiconductor. In this study, we have calculated the formation energy and transition levels of oxygen vacancies in β-Ga₂O₃ crystal using the B3LYP hybrid exchange-correlation functional within the LCAO-DFT approach. The obtained electronic charge redistribution in perfect Ga₂O₃ shows notable covalency of the Ga-O bonds. The formation of the neutral oxygen vacancy in β-Ga₂O₃ leads to the presence of deep donor defects with quite low concentration. This is a clear reason why oxygen vacancies can be hardly responsible for n-type conductivity in β-Ga₂O₃.