Tunable UV Absorption and Mobility of Yttrium-Doped ZnO using First-Principles Calculations

The electronic structures and optical properties of Y-doped ZnO are calculated using first-principles calculations. It is found that the replacement of Zn by the rare-earth element Y presents a shallow donor, and the Fermi level moves into the conduction band (CB). The high dispersion and s-type character of CB is expected to result in an increase in conductivity. Moreover, the absorption spectrum of the Y-doped ZnO system exhibits a slight blue shift with an increase of Y concentration, and a higher transparency in visible light is expected. Therefore, the Y-doping in ZnO would enhance the mobility and hence increase the electrical conductivity without sacrificing the optical transparency, which is essential for the improvement of ZnO's behavior and its performance in extension applications.