Side-chain engineering of conjugated molecules for n-type organic thermoelectrics

The growing need for renewable energy sources has led to increased interest in organic thermoelectric (OTE) materials, which are mechanically flexible, cost-effective to process, and capable of converting thermal energy into electricity. Although p-type OTEs have shown promising efficiency, the development of n-type OTEs has not kept pace with their p-type counterparts in terms of performance, highlighting the need for additional research and innovation. This review outlines the basic principles and molecular design strategies for n-type OTEs. It then examines side-chain engineering in-depth, underscoring the complementary effects of backbone and side-chain modifications. Lastly, it discusses the challenges and future directions in developing n-type OTEs to inform the design strategies for these materials.