Enhanced Thermoelectric Properties of Te Doped Polycrystalline Sn(0.94)Pb(0.01)Se

Thermoelectric materials can directly convert heat and electricity, which is a kind of promising energy material. In view of cost and mechanical properties, polycrystalline SnSe material with high zT value is greatly desired. In this study, polycrystalline Sn(0.94)Pb(0.01)Se(1-x)Te(x) samples were prepared by the vacuum melting–hot pressing sintering method. Sn vacancies, Pb and Te atoms were simultaneously introduced into the polycrystalline SnSe. The power factor of Sn(0.94)Pb(0.01)Se(1-x)Te(x) samples was decreased, which could be attributed to the generation of n-type semiconductor SnSe(2). In addition, the phonons were strongly scattered by point defects and dislocations, which led to the decrease of thermal conductivity—from 0.43 Wm(−1)K(−1) to 0.29 Wm(−1)K(−1) at 750 K. Finally, the polycrystalline Sn(0.94)Pb(0.01)Se(0.96)Te(0.04) sample achieved the maximum zT value of 0.60 at 750 K.