Realizing high thermoelectric performance in CeCl₃-doped n-type SnSe polycrystals

SnSe is a promising thermoelectric material because of its intrinsic low lattice thermal conductivity. However, the inferior electrical transport properties restrict the thermoelectric performance of n-type SnSe polycrystals especially at lower temperature range. In this work, an effective strategy to enhance the performance of n-type SnSe polycrystals by CeCl₃ doping is reported. CeCl₃ doping increased both the carrier concentration and electrical conductivity. The high weighted mobility contributed to the high power factor over the whole temperature range. Combined with the reduced thermal conductivity, a peak zT of ∼1.3 at 823 K was obtained in SnSe_0.92+1 mol% CeCl₃ with an average zT of ∼0.36 in the temperature range of 300–773 K. This work suggests that CeCl₃ doping is an effective way to optimize the thermoelectric properties of n-type SnSe polycrystals.