Preparation, characterization and infrared emissivity study of Ce-doped ZnO films

Ce-doped ZnO films were prepared by the sol-gel method with spin coating onto glass substrates. Zinc acetate dihydrate, ethanol, diethanolamine and cerium nitrate hexahydrate were used as starting material, solvent, stabilizer and dopant source, respectively. Structure and microstructure of the films were characterized with X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) and the energy dispersive X-ray spectrometry (EDS). The infrared properties were also investigated. It was found that Ce-doped ZnO films showed a hexagonal wurtzite structure and had a (101) preferred orientation. Metallic Ce existed in the form of CeO2, and the addition of Ce had an effect on the infrared emissivity of the films. The infrared emissivity increased with the temperature rising when the ZnO films were doped with 3 at.% and 7 at.% of Ce concentration. However, the infrared emissivity decreased with the temperature increasing when the ZnO film was doped with 5 at.% of Ce. It suggested that the infrared emissivity of the films was remarkably changed by controlling the Ce doping concentration.