Thermoelectric properties of p-type polycrystalline Bi0.8Sb0.8In0.4Se3

Abstract

Achieving both n-type and p-type performance in one thermoelectric material family is of great benefit for the thermoelectric device due to the comparable mechanical properties. Bi2Se3 shows strong n-type behavior due to the intrinsic Se vacancy. Herein, we reported a p-type poly-crystalline Bi0.8Sb0.8In0.4Se3 material, which has the same crystalline structure as Bi2Te3, with an intrinsic Seebeck coefficient of 500 μV K−1 at room temperature. It is found that Mn is a good p-type charge carrier provider in the as-fabricated Bi0.8Sb0.8In0.4Se3 thermoelectric material. An optimized power factor of ∼420 μW m−1 K−2 and a low thermal conductivity of 0.51 W m−1 K−1 result in a ZT of 0.48 at 350 °C in Mn0.03Bi0.77Sb0.8In0.4Se3. Our work provides an incisive insight into the manipulation of the intrinsic defects via high entropy strategy. This work was supported by the National Key Research and Development Program of China (Grant No. 2018YFB0703600), ECF under project (Grant No. 69/2018), and the Tencent Foundation through the XPLORER PRIZE. The theoretical calculations are supported by the research computing facilities offered by ITS, HKU.