Optimization of (002)-oriented ZnO film synthesis in sol-gel process and film photoluminescence property

By orthogonal design theory, technological parameters of the (002)-oriented ZnO film prepared in sol-gel process are optimized. A set of technological parameters for growing highly (002)-oriented ZnO film is obtained. As a result, it is proven that the Zn2+ concentration is the most important factor to grow a highly (002)-oriented ZnO film. We take an appropriate Zn2+ concentration 0.35 mol/L for the aimed film, of which photoluminescence property is better than those of the films derived from other Zn2+ concentrations precursor solution. The Zn2+ concentration either larger or smaller than 0.35 mol/L leads to the (002)-oriented degree decrease of films. By employing an atom force microscope, a hexagonal atom arrangement, which indicates that the film site detected is a ZnO single crystal, is observed in the surface of the highly (002)-oriented film.