Synthesis and characterization of zinc oxide thin films prepared by chemical the bath technique
Zinc oxide thin films were prepared with ammonia/ammonium chloride buffer as the reaction moderating agent in the chemical bath deposition technique. An observable color change during the reaction due to variations in the reactants concentration indicated the existence of the cupric (CuO) and cuprous (Cu2O) oxides phases. The surface structural characteristic was studied at an objective magnification of x 400. The elemental composition was determined using x-ray photoelectron spectroscopy (XPS), while the spectral characteristics of the optical parameters were obtained from the absorbance and transmittance data. The band gap energy of the samples deduced from the fundamental absorption edge gave the values of 1.60 – 2.80 eV for the direct
transition and 0.60 - 2.20 eV for the indirect transition. These values are close to those previously reported but the slight variation may be due to the concentration of the reactants, the effect of the buffer and the annealing process.
Keywords: Chemical bath technique, zinc oxide thin films, x-ray, photovoltaic cells