Preparation And Properties Of ZnO/SiO₂ Composite Thin Films

ZnO/SiO₂ and Ag-ZnO/SiO₂ composite thin films were deposited on glass substrates by means of sol-gel method.The samples were characterized by XRD,SEM,TEM,FT-IR, UV-Vis and PL,respectively.Structure and photoluminescent properties of the ZnO/SiO₂ composite thin films under the influence of different annealing temperature were studied,and the photoluminescent properties of ZnO/SiO₂ composite film with different concentration of ZnO were studied too. The result shows that high annealing temperature is good for the crystallization of samples and the reducing of structural defects.The particles become larger as the annealing temperature rise and partly reunion.The highest transmission composite film is annealed at 400℃.There are strong blue emission peaks of samples.The band gap changed and the emission peak intensity at ultraviolet and blue region increased with the concentration of ZnO increased.Ag-ZnO/SiO₂ composite thin films with Ag doped in ZnO layer were prepared.And the structure and photoluminescent properties of composite thin films under the influence of different Ag concentration were also discussed.The result shows that there is diffraction peak of Ag after annealed in air at 300℃as the content of Ag increased,the absorption peaks have red shift and widen because of the electron transfer between Ag and ZnO and the particle size of Ag becoming larger,that photoluminescent intensity of the films in the section of ultraviolet and visible region weakened with the content of Ag increased,and this is owing to the reduction of the hole concentration and the compensation of structural defects caused by the doping of Ag.