Preparation and Characterization of Electrochemical Deposition Cobalt Triantimonide (CoSb3) Thick Film: Effects of Polyvinyl Alcohol (PVA) as an Additive

A thick film of cobalt triantimonide (CoSb3) skutterudites was successfully synthesized via electrochemical deposition by using an electrolyte that contains antimony (Sb3+) and cobalt (Co2+) ions in a weak acid solution in the presence of polyvinyl alcohol (PVA) as an additive. The process was conducted under a potentiostatic condition of − 1000 mV versus Ag/AgCl at room temperature. Two hours (2 h) of electrochemical deposition produced a 13 μm assisted PVA CoSb3 thick film. In comparison, most studied electrochemical deposition of CoSb3 skutterudites thin films is in the thickness range of 700–800 nm. The morphological studies of the films appeared to have a cauliflower-like structure with a presence of fern-like dendrite for a non-PVA electrolyte due to the limitation of ion diffusion in the nucleation growth area. The absence of dendrite was observed in the assisted PVA films, which demonstrated an enhanced ion diffusion in the vicinity with a better stoichiometric ratio for Co:Sb of 1:3 thick film.