Effect of Ag Doping on Optical and Electrical Properties of ZnO Thin Films

ZnO thin films were prepared on p-type Si (100) substrates by the sol-gel process. The influence of Ag doping at a content of 0.002 % on the photoluminescence and current-voltage ( I − V ) characteristics of ZnO thin films has been investigated. It is found that Ag doping leads to a pronounced increase in the intensity of near band edge emission at 3.23 eV and a remarkable red shift of the visible broadband at room temperature. The I − V characteristics of ZnO/p-Si heterojunctions are also changed. These results could be explained by Ag substituting for Zn in Ag doped ZnO thin films.