ZnO nanoparticle films prepared by oxidation of metallic zinc in H2O2 solution and subsequent process

An efficient and size-controllable three-step method for fabricating ZnO nanoparticle films was described in this paper, which consists of: (1) oxidation of metallic zinc (Zn) in hydrogen peroxide (H2O2) solution, (2) spraying of the solution formed in step 1 onto substrates to form precursor films, and (3) annealing of the precursor films in the air to form ZnO nanoparticle films. The crystalline structure and the microstructure of the nanoparticle films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM), which indicated that ZnO nanoparticles are in wurzite structure with particle size in the range of 5-25 nm. The size of the ZnO nanoparticles in the films can be controlled by controlling the annealing temperature. In additon, the optical properties of ZnO nanoparticle films, including both UV-vis absorption and photoluminescence (PL), showed typical blue-shift as the gain-size decreased.