Electrodeposition and characterization of transparent ZnO thin films

Thin films of zinc oxide (ZnO) have been grown by potentiostatic cathodic deposition onto tin oxide-coated glass from a simple aqueous zinc nitrate electrolyte. Cyclic voltammetry (CV) experiments were performed to determine the reaction kinetics of the species. The various optimum deposition parameters like potential, pH and bath temperature are found to be −1.1 V (SCE), 5±0.1 and 80 °C, respectively. Structural characterization by X-ray diffraction indicates the formation of ZnO film with a preferred c-axis orientation and exhibits the wurtzite structure. Optical studies revealed a band gap energy 3.32 eV which is characteristic of ZnO films. SEM micrographs show a compact structure with nodular appearance, which is in agreement with the reported value of ZnO and the results are discussed.