  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.
