Nucleation mechanism and microstructural analysis of Zn films on Mo substrates by electrodeposition

Zinc (Zn) films have been prepared on a molybdenum (Mo) substrate by the electrodeposition method from the electrolyte solutions of zinc chloride (ZnCl₂) and potassium chloride (KCl) added by surfactant PEG-6000. The influence of growth conditions on growth kinetics, morphologies and phase constitution of the films were investigated by cyclic voltammetry (CV), chronoamperometry (CA), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Based on Scharifker-Hills model and microstructural analysis, it is found that the electrodeposition process of Zn films is mainly controlled by the diffusion process of zinc complex ions, and both progressive and instantaneous nucleation mechanisms are revealed and it is dependent on growth conditions such as main salt ZnCl₂ concentration and organic additive.