Structural and electronic properties of Y doped ZnO with different Y concentration.

We have performed a comprehensive calculation about the structures, energy band structures, total and partial density of states of Y doping ZnO with different concentration using the density-functional theory (DFT). The Y doping structures still maintain wurtzite configuration with the increasing of Y content. The research of formation energy shows that Y doping ZnO crystal is energetically stable, and the formation energies reduce with the increasing of Y molar content from 3.125% to 12.5%. The Y doping system exhibits direct band gap like pure ZnO. The Fermi level of doping ZnO crystal shifts upward into conduction, showing the properties of n-type semiconductor and the band gaps of Y doping are larger than that of pure ZnO. There exists a strong localized state at near 5 eV in conduction band, which mainly comes from Y-4d states. The DOS of concentration 12.5% appears a new strong peak at near −24 eV, which mainly originates from the Y-4p states. [ABSTRACT FROM AUTHOR]