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

Applied Physics Letters, Volume 118, Issue 19, May 2021. 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.