Electrostatic spray deposited polycrystalline zinc oxide films for ultraviolet luminescence device applications

Zinc oxide polycrystalline films were prepared by electrostatic spray deposition using the dispersions of zinc oxide nanocrystals as solution precursors for ultraviolet luminescence device applications. The structure and properties of the films were studied by X-ray diffraction, scanning electron microscope, energy dispersive X-ray spectroscopy and photoluminescence. Room temperature photoluminescence spectra of these films exhibit a strong near band-edge emission at 380 nm and a negligible deep-level emission around 530 nm, indicating the concentrations of the defects responsible for deep-level emissions are reduced on annealing. Moreover, temperature dependence of photoluminescence of ZnO film was investigated.