Organic Thermoelectrics: Materials Preparation, Performance Optimization, and Device Integration

Green technology has attracted much attention in recent years due to the fear of exhaustion of traditional fossil sources and the rising awareness of environmental protection. Thermoelectric (TE) technology is an auxiliary energy technique that can directly convert waste heat to electricity through TE generators. This green energy-saving technology is considered to be a promising way to relieve the pressure of energy and environment. TE generators have significant advantages of durability and simplicity over conventional power generators because of their unique solid-state structures. The global market growth of TE generators is rapid and will reach over $950 million by 2024 (Zervos). Specifically, organic TE generators offer additional benefits of light weight, flexibility, and low-cost production. The performance of TE generators depends on the performance of TE materials, which is determined by the Seebeck coefficient, electrical conductivity, and thermal conductivity. A good TE material requires a high Seebeck coefficient, high electrical conductivity, and low thermal conductivity. However, these three parameters are strongly correlated with each other, which inhibits the improvement of the performance of TE materials. In this review, recent advances in materials preparation, performance optimization, and device integration are highlighted, and an outlook on the future development in organic thermoelectrics is provided.