Effect of ZnCl₂ concentration on the growth of ZnO by electrochemical deposition

ZnO thin films were prepared by an electrochemical deposition route on Zn/Si substrates. The effect of zinc chloride concentration on the optical and structural properties of ZnO was investigated. With the increase of concentration of ZnCl₂, the morphologies of ZnO thin films were varied from thin films to sheet-like shapes. For low concentrations less than 10 mM, the dense ZnO thin films with the nano-sized grains were formed. For high concentrations above 50 mM, the films was composed of large plates of Zn ₅(OH)₈Cl₂ and their morphologies were strongly affected by thermal annealing. According to X-ray diffraction (XRD) and photoluminescence (PL) results, the crystallinity of ZnO thin film was significantly improved through annealing at 300°C. Crown