Effects of oxygen vacancy on optical and electrical properties of ZnO bulks and nanowires

Based on the generalized gradient approximation (GGA) in density functional theory (DFT) and using the first-principle plane wave ultrasoft pseudopotential method, we construct and optimize the structures of intrinsic and oxygen vacancy (V_O) ZnO bulks and nanowires (NWs) in the Castep module. Moreover, the calculation of band structures and the optical properties are carried out. The calculated results exhibit that the oxygen vacancy exerts a more significant influence on the electronic structures of the ZnO bulks instead of the NWs. What is more, the influences of the V_O on the optical properties are mainly embodied in the ultraviolet region, and the main optical parameters of ZnO bulks and NWs with V_O are anisotropic.