Enhancement of the thermoelectric properties of Bi2Te3 nanocrystal thin films by rapid annealing

Abstract In this work, stoichiometric Bi2Te3 thin films were successfully prepared on a polymer substrate by using single-source evaporation method. Rapid annealing was applied to improve the crystallinity and control the grain size of the thin films, thereby conferring them with high thermoelectric performance. As expected, the prepared thin films revealed a pure Bi2Te3 phase with nanosized grains. Consequently, a substantially enhanced power factor and reduced lattice conductivities resulting in a high ZT value of 0.5 was achieved. The results of the present work provide novel insights into the development of high-performance thermoelectric thin films through thermal control of crystallinity and grain size.