Effects of Cu doping on the surface morphology, microstructure and photoluminescent characteristics of ZnO films

Cu-doped ZnO thin films with a single phase (002) oriented were prepared on glass substrate by magnetron co-sputtering. The influences of Cu doping on the microstructure, surface morphology and photoluminescent characteristics of the films were systematically investigated. XRD and SEM results show that the moderate Cu doping could promote the preferential growth of (002) crystal plane and help Cu atoms orderly merge into lattice of ZnO, but the excessive Cu doping inhibits it. The blue emissions peaks were mainly originated from the transition from the conduction band bottom to Zinc vacancy and the transition from antisite Zinc to zinc vacancy. We can control the intensity of blue emissions peaks by changing the Cu doping content.