Recent advances in molecular design of organic thermoelectric materials

Organic thermoelectric (OTE) materials have gained widespread attention because of their potential for wearable power generators and solid cooling elements. Nevertheless, the development of state-of-the-art OTE materials still suffers from limited molecular categories because of the rarity of molecular design strategies, which limits further development of this emerging field. Recently, many efforts have been devoted to developing molecular design concepts for high performance OTE materials. In this mini review, we present the fundamentals of the thermoelectric (TE) effect and the basic guidelines for designing OTE materials based on doped semiconductors. Subsequently, we provide an overview of the molecular design of conjugated backbones and side chains for enabling efficient TE conversion, including the effects of the molecular framework, heteroatomic substitution, and side chain length and polarity. Finally, we emphasize the developing tendency of molecular engineering towards high-performance and multifunctional OTE materials.