Electrodeposition of Sb-Te Thermoelectric Material in Ethylene Glycol Non-Aqueous Solution

Abstract

The electrodeposition of antimony-tellurium binary alloy with thermoelectric conversion properties was attempted in non-aqueous solutions using ethylene glycol（EG）as a solvent. The EG-based electrolytic baths consisted of antimony chloride（SbCl₃）as an antimony ion source and tellurium chloride（TeCl₄）as a tellurium ion source. The composition of the electrodeposits was controlled by the molar ratio of SbCl₃ to TeCl₄ in the bath and the current density. As a result, Sb₂Te₃ was identified by XRD in the electrodeposit obtained at 20Am^－2 in the 97.50 mol% EG-2.45 mol%SbCl₃-0.05 mol%TeCl₄ bath with a SbCl₃ to TeCl₄ molar ratio of 50：1. The composition of the electrodeposit was found to be 42.62 mol%Sb-57.38 mol%Te. The electrodeposit exhibited a p-type thermoelectric conversion for the given temperature difference.