Phonon and Carrier Transport Properties in Low-Cost and Environmentally Friendly SnS₂: A Promising Thermoelectric Material

Recently, low-cost and environmentally friendly materials have attracted increasing attention in the thermoelectric community. SnS2 as a sister compound of SnS with abundant and nontoxic elements exhibits a layered crystal structure and large bandgap, making it a promising thermoelectric material. In this review, we systematically introduce some intrinsic properties of the SnS2 compound, including the crystal structure, preparation method, microstructure feature, and phonon and carrier transport properties. Because SnS2 is an emerging thermoelectric material with few experimental investigations in thermoelectric properties, we highlight the preparation methods of both the polycrystalline and single-crystal SnS2, which could facilitate its further developments. From the theoretical calculation results, the layered crystal structure in SnS2 leads to strong anisotropic thermal and electrical transport properties, and competitive thermoelectric performance can be achieved in both bulk and nanosheet forms with optimal carrier concentration. Furthermore, the favorable phonon spectrum and electronic band structure in SnS2 make its thermoelectric performance expected in future investigations. Finally, some promising strategies are proposed toward future enhancements of the thermoelectric performance in SnS2 compound.