Effect of sodium p-type doping on the structural, electrical and optical properties of zinc oxide

Abstract

Electronic and optical properties of Na doped zinc oxide (ZnO:Na) were calculated with the FP-LAPW method by using the LSDA approximations. The lattice constants of ZnO calculated in this study is in a good agreement with experimental and theoretical values. The band gap was increased slightly by doping with Na impurity. Furthermore, we calculated the density of states of Na doped ZnO. The results show that acceptor concentration increases with an increase in Na concentration. Na doping introduces a much shallow acceptor (above the Fermi level), which is of typical p-type behavior. On the other hand, the refractive index, the dielectric function, and the absorption coefficient were determined and show a good agreement with available experimental data. Sodium doping leads to an optical peak at about 395nm. We found that the intensity of this optical peak increases by the incorporation of Na into ZnO. That peak might improve the optical characteristics of ZnO for solar cell and optical applications.