First-principles study on electronic structure and optical properties of N-doped P-type βGa ₂O ₃

The band structure, density of states, electron density difference and optical properties of intrinsic βGa ₂O ₃ and N-doped βGa ₂O ₃ were calculated using first-principles based on density functional theory. After N doping, the band gap decreases, shallow acceptor impurity levels are introduced over the top of the valence band and the absorption band edge is slightly red-shifted compared to that of the intrinsic one. The anisotropic optical properties are investigated by means of the complex dielectric function, which are explained by the selection rule of the band-to-band transitions. All calculation results indicate that N-doping is a very promising method to get P-type βGa ₂O ₃.