Thermoelectric properties of Bi2Te3 thin films prepared by thermal evaporation method

Bi2Te3 compounds are known to be the best thermoelectric materials within room temperature region, which exhibit potential applications in cooler or power generation. In this paper, the Bi2Te3 thin filmswere prepared on SiO2/Si substrates by thermal evaporation method. The influence of substrate temperature on the microstructures and thermoelectric properties of Bi2Te3 thin films were investigated. The crystalline structures and morphologies were characterized by X-ray diffraction and field emission scanning electron microscope analyses. The Seebeck coefficients, electrical conductivity and power factor were measured at room temperature. The experimental results showed that both the Seebeck coefficient and power factor enhanced as the substrate temperature increases. When the substrate temperature increased to 423K, the Seebeck coefficient and power factor of n-type Bi2Te3-based films were found to be about -88.83 mu V/K and 4.89 mu W/cm . K-2, respectively.