Progress in the study of binary chalcogenide-based thermoelectric compounds

As a novel and environmentally friendly energy source, thermoelectric (TE) materials are receiving more and more attention because of their unique capability to directly convert heat into electricity. Chalcogenide-based materials have been extensively explored as promising TE candidates in the past years, primarily attributed to their unique properties in accommodating diverse compositions and structures, resulting in exceptional TE performance. Enhancing the TE properties of such materials typically involves a series of strategies: optimizing carrier concentration, harnessing energy band engineering to decouple the Seebeck coefficient and electric conductivity, and lowering the lattice thermal conductivity via nanostructuing. These approaches collectively hold the potential to significantly boost the overall performance of chalcogenide materials. This review provides a comprehensive overview of several classical chalcogenide-based TE material systems, such as SnQ (Q = S, Se, Te), PbQ (Q = S, Se, Te), GeTe, and Bi2Te3, focusing on their structures, and elucidates strategies for enhancing their thermoelectric performance.