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

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 °C. This was due to the formation of Te nanodots in the Sb₂Te₃ matrix. The resulting Sb₂Te ₃ 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 μW m^-1 K ^-2, which was about two times higher than that of Sb ₂Te₃ 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.