Optimized thermoelectric properties of flexible p-type Sb2Te3 thin film prepared by a facile thermal diffusion method

Sb2Te3-based thermoelectric thin film is a competitive candidate for preparing thermoelectric thin film devices, which power the wearable electronic devices and chip-sensor of internet-of-things. In this work, a directed thermal diffusion reaction method was applied to synthesize p-type Sb2Te3 thin films synthesis at polyimide flexible substrate with self-assembled growth. A high power factor of 1.94 mWm−1K−2 with excellent flexibility which is very competitive among similar Sb2Te3 based materials by the control of synthesis condition, especially the chemical composition. Meanwhile, the performance of thermoelectric thin film device is limited by contact resistance. Thus the more systematic study of contact resistance, including choice of electrode material for the device was investigated. The results indicate that Mo/Sb2Te3 have the lowest contact resistivity compared with Al/Sb2Te3 and Ni/Sb2Te3. In addition, the fabricated flexible device with Mo electrode has outstanding thermal stability.