Electronic structures and optical properties of Zn-doped β-Ga₂O₃ with different doping sites

The electronic structures and optical properties of intrinsic β-Ga₂O₃ and Zn-doped β-Ga₂O₃ are investigated by first-principles calculations. The analysis about the thermal stability shows that Zn-doped β-Ga₂O₃ remains stable. The Zn doping does not change the basic electronic structure of β-Ga₂O₃, but only generates an empty energy level above the maximum of valence band, which is shallow enough to make the Zn-doped β-Ga₂O₃ a typical p-type semiconductor. Because of Zn doping, absorption and reflectivity are enhanced in the near infrared region. The higher absorption and reflectivity of Zn_Ga(2) than those of Zn_Ga(1) are due to more empty energy states of Zn_Ga(2) than those of Zn_Ga(1) near E_f in the near infrared region.