Improved thermoelectric properties of SnS synthesized by chemical precipitation

Abstract

Sulfur compounds have been considered as potential thermoelectric materials due to recently reported high ZT values. However, the synthetic methods for these compounds are too expensive or complicated to be applied to large-scale production. Among these compounds, tin sulfide (SnS) has attracted increasing attention not only because of its extremely low thermal conductivity (below 1.0 W (m K)⁻¹) but also its earth-abundant resources. Mechanical alloying and solvothermal method have been adopted to synthesize SnS as thermoelectric materials, but these preparation processes are either expensive or complicated. Here, a simple chemical precipitation method was developed to synthesize high-performance SnS by using analytically pure compounds as raw materials. The highest ZT value of 0.41 with a very low thermal conductivity of 0.29 W (m K)⁻¹ and a large Seebeck coefficient of 403 μV K⁻¹ is obtained at 848 K. The ZT value is two times higher than that of SnS samples synthesized by mechanical alloying, and our work provides a simple new method to obtain SnS with high ZT value, which will help its mass production in the future.