Ab initio investigation on intrinsic Ga vacancies in β-Ga2O3 utilizing hybrid functional combined with the shell DFT-1/2 approach

The monoclinic crystal system β-gallium oxide (β-Ga₂O₃) is an advantageous semiconductor, characterized by a substantial bandgap of approximately 4.8 eV, exceptional stability under ambient conditions, and transparency to ultraviolet (UV) light. In practical applications, it is critical to effectively manage defects within β-Ga₂O₃. Failure to rigorously control defect types and concentrations can significantly compromise device stability and reliability. Among the prevalent and impactful defects, Ga intrinsic vacancies notably affect the optoelectronic performance of β-Ga₂O₃, yet they have not been comprehensively studied using suitable generalized approximations. This paper systematically examines the electronic and optical properties of β-Ga₂O₃ with intrinsic Ga vacancies using hybrid functional methods combined with the shell DFT-1/2 approach. Key properties analyzed include electronic bandgap and density of states, structural properties like elastic constants and phonon dispersion, and optoelectronic properties such as permittivity, absorption spectra, and electronic energy-loss spectra. Detailed discussion is provided on the formation energy curves of these Ga intrinsic defects.