Thermoelectric characteristics of Sb2Te3 thin films formed via surfactant-assisted electrodeposition

Abstract

In this study, Sb2Te3 films were electrodeposited potentiostatically at room temperature from acidic nitric baths in the presence of a surfactant, cetyltrimethylammonium bromide (CTAB). This resulted in improvements in the surface morphologies of the films. The thus-deposited films also exhibited better adherence to their substrates. In addition, the carrier transport properties of the Sb2Te3 films, including their electrical conductivities and Seebeck coefficient values, could be improved by annealing them at 200 degrees C. This was due to the formation of Te nanodots in the Sb2Te3 matrix. The resulting Sb2Te3 films with Te nanodots 10-20 nm in size and a dispersion density of 11.4 vol% exhibited a high power factor of 716.0 mW m(-1) K-2, which was about two times higher than that of Sb2Te3 films that did not contain Te nanodots. The results of the study suggested that the improvements in the thermoelectric characteristics of the films were due to carrier energy filtering at the Te-Sb2Te3 interface.