Effect of Potential on Structural, Morphological and Optical Properties of ZnO Thin Films Obtained by Electrodeposition

Abstract

Polycrystal ZnO thin films have been deposited on ITO coated glass substrate in two different potential of -0.85 V and -0.95 V by electrochemical deposition technique using 0.005 M ZnCl2 or 0.01 M (Zn(NO3)2·6H2O) at 72 ± 2 ºC and with supporting electrolyte 0.1 M KCl aqueous solutions. Before the depositions, the solutions were saturated with oxygen by passing oxygen through the growth cell. The energy band gaps of the obtained films were estimated from the absorbance measurements. The energy band gaps of the films obtained using Zn(NO3)2 were between 3.49 and 3.57 eV while that of obtained using ZnCl2 were between 3.60 and 3.63 eV. XRD (X-ray diffraction) results showed that all the films have a hexagonal structure. It was obtained by XRD that the crystallite sizes of the films are between 46 and 54 nm. Morphological characterization of the ZnO thin films was characterized from the SEM (Scanning electron microscopy) images. It is seen from the SEM images that the surface of the films are leafy and flaky form.