Enhanced thermoelectric performance of SnSe based composites with carbon black nanoinclusions

Recently, single crystalline SnSe and its sodium doped compound were reported to have an ultralow thermal conductivity and high thermoelectric figure of merit. However, the highest high thermoelectric figure of merit for polycrystalline SnSe-based materials is not larger than unity. In this study, we report a high thermoelectric figure of merit 1.21 at 903K along the hot pressing direction for polycrystalline SnSe, realized by incorporating a proper proportion of carbon black as nano-inclusions. The exceptional performance arises from the ultra-high power factor, which comes from a high electrical conductivity and an enhanced Seebeck coefficient through energy-dependent scattering.