Enhanced thermoelectric performance in n-type polycrystalline SnSe by PbBr2 doping

Abstract

A series of PbBr2-doped polycrystalline SnSe samples were synthesized by melting and hot pressing. By PbBr2 doping, the carrier concentration of SnSe was increased to 1.86 × 1019 cm−3 from 2.41 × 1017 cm−3, resulting in an increased electrical conductivity of 40 ± 2 S cm−1 at 713 K while the undoped SnSe was only 5.1 ± 0.3 S cm−1. Meanwhile, the PbBr2-doped samples also exhibit a larger density of state effective mass (0.812m0). Therefore, a high power factor of 4.8 ± 0.5 μW cm−1 K−2 and a peak ZT of 0.54 ± 0.1 were achieved at 793 K perpendicular to the hot pressing direction.