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 SnSe0.92+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.