Study on the Thermoelectric Properties of n-Type Polycrystalline SnSe by CeCl3 Doping

SnSe is a promising medium-temperature thermoelectric material due to its extremely low thermal conductivity and tunable electronic transport properties. In this work, n-type SnSe0.95 polycrystals doped with CeCl3 are synthesized by a melting method combined with a spark plasma sintering (SPS) process. The samples have highly textured structures and anisotropic thermoelectric properties. CeCl3 doping has a favorable effect on the electronic transport above 473 K, which may benefit from the excitation of the introduced impurity energy level. Moreover, the thermal conductivity is significantly reduced due to the phonon scattering by point defects. Finally, a peak ZT value of 1.17 is obtained at 773 K in SnSe0.95–0.5 mol % CeCl3, which paves the way for improving the thermoelectric performance of n-type SnSe via rare-earth halide doping.