Radiation damage effects on electronic and optical properties of β-Ga2O3 from first-principles.

β-Ga₂O₃ with an ultra-wide bandgap demonstrates great promise in applications of space missions as power electronics and solar-blind photodetector. Unraveling the radiation damage effects on its material properties is of crucial importance, especially for improving the radiation tolerance of Ga₂O₃-based devices. Herein, we evaluate the formation energy of gallium and oxygen vacancy defects and comprehensively investigate their influence on the electronic and optical properties of β-Ga₂O₃ using first-principles calculations. Ga vacancies act as deep acceptors and produce p-type defects in β-Ga₂O₃, while the defective Ga₂O₃ with O vacancies exhibits the n-type characteristics. A semimetal characteristic is observed in the defective Ga₂O₃ with Ga vacancies, and an apparent optical absorption peak in the infrared spectral range emerges. Moreover, the self-compensation effect emerges when β-Ga₂O₃ contains both Ga vacancies and O vacancies, leading to the reduced absorption peak. The doping effect on the defect formation energy of β-Ga₂O₃ is also investigated, and Ga vacancies are found to be easily formed in the case of In doped β-Ga₂O₃ (InGa₂O₃) compared to the undoped β-Ga₂O₃, while O vacancies are much harder to form. This work provides insights into how gallium and oxygen vacancy defects alter electronic and optical properties of β-Ga₂O₃, seeking to strengthen its radiation tolerance. [ABSTRACT FROM AUTHOR]