Recent progress in design of conductive polymers to improve the thermoelectric performance

Organic semiconductors, especially polymer semiconductors, have attracted extensive attention as organic thermoelectric materials due to their capabilities for flexibility, low-cost fabrication, solution processability and low thermal conductivity. However, it is challenging to obtain high-performance organic thermoelectric materials because of the low intrinsic carrier concentration of organic semiconductors. The main method to control the carrier concentration of polymers is the chemical doping process by charge transfer between polymer and dopant. Therefore, the deep understanding of doping mechanisms from the point view of chemical structure has been highly desired to overcome the bottlenecks in polymeric thermoelectrics. In this contribution, we will briefly review the recently emerging progress for discovering the structure-property relationship of organic thermoelectric materials with high performance. Highlights include some achievements about doping strategies to effectively modulate the carrier concentration, the design rules of building blocks and side chains to enhance charge transport and improve the doping efficiency. Finally, we will give our viewpoints on the challenges and opportunities in the field of polymer thermoelectric materials.