Abstract Antimony telluride (Sb 2 Te 3 ) is a chalcogenide material used in thermoelectric applications. The deposition of thin films of Sb 2 Te 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 2 Te 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 2 Te 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 2 V −1 s −1 ) were measured at room temperature for the best Sb 2 Te 3 thin-films.