Thermal co-evaporation of Sb 2Te 3 thin-films optimized for thermoelectric applications

Abstract

Antimony telluride (Sb 2Te 3) is a chalcogenide material used in thermoelectric applications. The deposition of thin films of Sb 2Te 3 requires a precisely controlled process to achieve a desirable high thermoelectric figure-of-merit. The optimization of the thermal co-evaporation process for p-type Sb 2Te 3 thin-film onto plastic substrates (Kapton© polyimide) for thermoelectric applications is reported. The influence of deposition parameters and composition on thermoelectric properties was studied, seeking optimal thermoelectric performance. Energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy all confirmed the formation of Sb 2Te 3 thin films. Seebeck coefficient (up to 190 μVK −1), in-plane electrical resistivity (8–15 μΩm), carrier concentration (1 × 10 19–7 × 10 19 cm −3) and Hall mobility (120–180 cm 2V −1s −1) were measured at room temperature for the best Sb 2Te 3 thin-films.