Defect energetics and electronic structures of As-doped p-type ZnO crystals: A first-principles study

First-principles calculations based on density functional theory have been carried out to understand the mechanism of fabricating As-doped p-type ZnO semiconductors. It has been confirmed that AsZn-2VZn complex is the most plausible acceptor among several candidates for p-type doping by computing the formation and ionization energies. The electronic band structures and atomic-projected density of states of AsZn-2VZn defect complex-contained ZnO bulks have been computed. The acceptor level in AsZn-2VZn band structure has found to be 0.12 eV, which is in good agreement with the experimental ionization energy (0.12 ~ 0.18 eV). The hybridization among O 2p, Zn 3d and As 4s states has been observed around the valence band maximum.