Synthesis and Thermoelectric Properties of SnSe by Mechanical Alloying and Spark Plasma Sintering Method

Abstract

The bulks of polycrystalline SnSe materials were successfully prepared by the mechanical alloying (MA) and spark plasma sintering (SPS) method. X-ray powder diffraction analysis showed that pure Sn and Se powders were synthesized into the SnSe phase by MA, and after SPS under 30–120 MPa, the single phase bulks of SnSe materials were successfully prepared. Scanning electron microcopy images displayed that the grain size of SnSe shows refinement with higher pressure. The electrical properties of the sintered samples increased with increasing sintering pressure. The thermal conductivity results show that the thermal conductivity remained low, in the range of 0.50–0.85 W m−1 K−1, with the different sintering pressure. The samples sintered under 100 MPa have the best thermoelectric properties; the dimensionless figure of merit ZT reached 0.71 at 873 K.