Preparation and Thermoelectric Properties of Nano-Bismuth Telluride Film by High-Temperature Thermal Shock

Abstract

Thermoelectric materials can directly convert thermal energy into electrical energy, realizing the recovery of waste heat. Bismuth Telluride (Bi-Te) is considered as a perfect candidate thermoelectric material which has great potential in the field of refrigeration and temperature sensor. However, in the field of intelligent wearable devices and integrated circuits, traditional Bi-Te block material is difficult to be directly used due to its poor flexibility. In this paper, a series of Bi-Te thin films were prepared by a self-designed high-temperature thermal shock equipment. This equipment can heat up the reduced graphene oxide strip to 1750 K in 20 ms, which features both high heating rate (8.2 × 104 K/s) and cooling rate (1.5 × 104 K/s). Thermoelectric films on different substrates were prepared via high-temperature thermal shock. Through regulating the temperature of evaporation source, the particle size and composition of Bi-Te thin films can be precisely modulated, thus optimizing the Seebeck coefficient of the films. The Seebeck coefficient of copper foil (Cuf)-based Bi-Te film can reach 345.41 μV/K, which was prepared by thermal-shocking the Bi-Te powders for 30 s at 900°C.