Electronic properties of ZnO doped by rare-earth elements from first-principles

We perform first-principles calculations to investigate the band structure and density of states of rare-elements doped ZnO. The calculated results show that the shapes of band structures for ZnO by rare-element doping are similar. And the rare-elements incorporation has a little influence on the band gap of the doping system under our considered doping concentration, but after doping, the Fermi level goes into the conduction band, and the electrons from the conduction band minimum to the Fermi level are increasing after rare-earth doping, which means that rare-element doping can change the electrical conductivity of ZnO to a great extent. Meanwhile, it is found that the conduction band near the Fermi level is determined by the rare-element-d states and O-p states, demonstrating as a strong hybridization. This study could provide a theoretical explanation for the factors influencing the properties of ZnO.