Preparation and properties of Nanostructure Zinc Oxide Thin Films


Zinc Oxide (ZnO) is probably the most typical II-VI semiconductor, which exhibits a wide range of nanostructures. In this paper, polycrystalline ZnO thin films were prepared by chemical spray pyrolysis technique, the films were deposited onto glass substrate at 400 °C by using aqueous zinc chloride as a spray solution of molar concentration of 0.1 M/L.
The crystallographic structure of the prepared film was analyzed using X-ray diffraction; the result shows that the film was polycrystalline, the grain size which was calculated at (002) was 27.9 nm. The Hall measurement of the film studied from the electrical measurements show that the film was n-type. The optical properties of the film were studied using measurements from VIS-UV spectrophotometer at wavelength range (300-1100) nm; the optical characterization shows that the films have an average transmittance 55% in the VIS regions. The refractive index was calculated as a function of the photon energy, also the calculated optical energy gap was 3.3 eV and 3.1 eV for direct and indirect allowed transition respectively.