The Cooperative Effect of Ag and Cu Co-doping on Morphology and Optical Properties of ZnO Nanorods

Zinc oxide (ZnO) has unique physical and optical properties. Proper doping of ZnO plays an important role in adjusting the photoelectric properties of its optoelectronic devices. In this paper, undoped, Ag-or Cu-doped, and Ag+Cu co-doped ZnO nanorod (NRs) arrays were synthesized by hydrothermal method at low temperature. Meanwhile the influence of doping and co-doping on the morphology, structure, and optical properties of ZnO NRs was investigated. The results show that the ZnO NRs prepared under different doping conditions were of wurtzite structure with strong (002) diffraction peak, and the diffraction peak of Ag+Cu co-doped ZnO NRs was similar to that of undoped ZnO NRs, which was due to the synergistic effect of lattice distortion caused by smaller radius Cu2+ doping and larger radius Ag+ doping than Zn2+. Affected by the size effect of nanorods and the Band Gap Renormalization effect, the UV emission peaks of all doped ZnO NRs had a red shift. Compared with that of undoped ZnO NRs, the intensity of visible emission peak of co-doped ZnO NRs increased slightly owing to the increasing defect concentration such as oxygen vacancy, and lay between that of AZO NRs and CZO NRs. Therefore, the co-doping of Ag and Cu makes it possible for ZnO NRs to be widely used in photoelectric field.