Enhanced Thermoelectric Properties of Te Doped Polycrystalline SnPbSe.

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 value is greatly desired. In this study, polycrystalline SnPbSeTe 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 SnPbSeTe samples was decreased, which could be attributed to the generation of -type semiconductor SnSe. In addition, the phonons were strongly scattered by point defects and dislocations, which led to the decrease of thermal conductivity-from 0.43 WmK to 0.29 WmK at 750 K. Finally, the polycrystalline SnPbSeTe sample achieved the maximum value of 0.60 at 750 K.