Realization of high power factor in polycrystalline In doped Sb2Te3 thin films for wearable application

Abstract

Te-based materials exhibit outstanding thermoelectric performance at room temperature, promising candidates for the fabrication of the wearable electronic devices and chip-sensor of internet-of-things. In this work, a combination of magnetron co-sputtering and post-tellurization methods was used to prepare In doped Sb2Te3 thin films. A high carrier concentration is ascribed to the increase in the density of states after In doping proved by first-principles calculations and experiments, which leads to an increase in the electrical conductivity of ∼1686.84 S cm−1 and moderate S above ∼105.24 μV K−1. Consequently, a peak power factor of 18.68 μW cm−1 K−2 was realized in In doped Sb2Te3 thin films at 300 K, representing a ∼17% increase compared to the undoped samples. After 1000 bending cycles, the relative resistance evolution lower than 2% and relative S evolution lower than 5% exhibit excellent flexibility of In-doped flexible thermoelectric film. The fabricated thermoelectric device generated an output power of 65 nW with a temperature difference of 20 K.