Review of current ZT > 1 thermoelectric sulfides

Thermoelectrics has played a fascinating role in the developments of direct energy conversion technologies. Over the past decade, sulfur-based thermoelectric materials have been significantly advanced in optimizing electrical and thermal transport due to their similarities in chemical and structural properties with tellurides and selenides. This review provides research progress on metal sulfides, particularly focuses on materials exhibiting high thermoelectric figure of merit (ZT > 1.0). It highlights the potential compounds, e.g. CuS, SnS, PbS based, and polysulfides. Great strategies of superionic conducting, band configuration tuning, high-entropy alloying, and anomalous harmonic scattering are try to demonstrate the performance-improved mechanisms for thermoelectric sulfides. In addition, some common synthesis recipes are briefly introduced, and thereby making potential candidates as excellent alternatives for producing thermoelectric power generators in the mid temperature. Key outcomes along with how to further improve the thermoelectric performance and promote its scale-up applications are also outlined at the end.