The effect of thikness on the structural and optical properties of ZnO thin films Prepared by chemical spray pyrolysis methode

ZnO thin films have been prepared on glass substrates at 400°C substrate temperature by the chemical spray pyrolysis(CSP) method using an aqueous solution with varying diffrent thickness. The films have been characterized to evaluate the structure ,transmittance and optical energy band gab. X-ray diffraction(XRD) studies show that the films are polycrystalline with hexagonal structures. The grain size of the films was found increased with increasing the thickness values. The optical band gab energies and types of optical transition and absorption of the films have been determined from the optical transmittance spectra. The optical absorption studies in the wavelength range 400–1100 nm show that band gap energy values of the films decrease from (2.5-2.35 )eV as the thickness increases.