Electrodeposition of Co–Sb thermoelectric film from ethylene glycol–CoCl2–SbCl3 solution

The electrodeposition of cobalt–antimony thermoelectric semiconductor films was investigated in a non-aqueous solution of ethylene glycol (EG)–CoCl2–SbCl3 at 393 K. By controlling the bath composition and cathodic current density, Co–Sb alloys containing 0–94 mol% of Co were obtained at 50–300 Am− 2. The resistance polarization caused by the formation of semiconductor film was observed in the polarization curve measured in the EG–CoCl2–SbCl3 (90.0–9.3–0.7 mol%) bath. In this bath, the Co–Sb (23.6–76.4 mol%) alloy was obtained by maintaining the constant potential electrolysis at 0.1 V. This alloy included CoSb3 and exhibited a p-type thermoelectric conversion by the given temperature difference.

► Electrodepotion of the Co-Sb thermoelectric film in ethylene glycol based solution.
► Various composition of Co-Sb alloys were obtained by electrolysis consitions.
► Co–Sb alloy containing CoSb3 were obtained at specific condition.
► Co–Sb alloy obtained in this study exhibited a p-type thermoelectric conversion.