Deposition of nanostructure ZnO film depending on the different preparation conditions using sol gel method and its physical characterization

In this work, nanostructure ZnO films were deposited onto the glass substrates atdifferent temperatures and pH values by using the sol gel spin coating method. Theinfluence of temperature and pH on the structural, optical and morphologicalproperties of the nanostructure ZnO films were investigated. The texture coefficient(TC) and the average crystallite size were calculated using the XRD patterns of theZnO films. The films have a polycrystalline structure and (002) preferredoriantation. A sharp increase was observed in the absorption spectra of the films atabout 390nm. All the films showed an average transmittance of 85% in the visibleregion. The optical band gaps of the nanostructure ZnO films were determined byusing the analysis of optical absorption spectra. The direct allowed optical band gapsof the films were found to be between 3.23 and 3.29eV. It was observed that theoptical band gaps of the ZnO films obtained at 50°C temperature tended to increasewith increasing the pH value. The surface morphology of the nanostructure ZnOfilms were investigated by using scanning electron microscopy (SEM) at threedifferent magnifications. It was observed that the films deposited at at 50°Ctemperature was not more affected by the change pH value, the homogeneity of thesurface is usually protected and the crytallite size decreased with increasing the pHvalue.