First-Principles Calculations of the Electronic Structure and Optical Properties of Y-Cu Co-Doped ZnO

Using the pseudo-potential plane-wave based on the density functional theory (DFT), the electronic structures and optical properties of intrinsic ZnO, Y-, Cu-, and Y-Cu co-doped ZnO were studied. The results show that the conductivity of ZnO can be improved by Y and Cu doping because of the increase in carrier concentration under the order of magnitude of the doping concentration in this paper. Y-Cu co-doping leads to degeneration and makes ZnO metallic. Y-doped ZnO can show enhanced light absorption in the ultraviolet region, while doping with Cu enhances absorption in the visible and near ultraviolet regions. Y-Cu co-doping greatly increases the absorption of visible and near ultraviolet regions owing to the synergistic effect between Y ions and Cu ions, which can be exploited to fabricate the opto-electronic devices.