Organic Semiconductors for Thermoelectric Modules: Potential, Limitations and Engineering Perspectives

Abstract

Thermoelectric (TE) devices enable direct conversion between heat and electricity and offer a solid state approach to waste heat recovery and localized cooling. Conventional TE modules are dominated by inorganic semiconductors such as Bi₂Te₃ based alloys, which provide high performance near room temperature but are mechanically brittle and rely on materials with supply and environmental concerns. In recent years, organic semiconductors—particularly conducting polymers, molecular semiconductors, and polymer–carbon nanofiller composites—have emerged as promising candidates for lightweight, mechanically flexible, and potentially more sustainable thermoelectric systems. This review evaluates the potential of organic TE materials to complement or partially replace traditional inorganic semiconductors in TE modules. Key performance parameters (Seebeck coefficient, electrical conductivity, thermal conductivity, power factor, and figure of merit ZT) are discussed together with engineering constraints such as stability, reproducibility, processing routes, contact resistance, and device integration. The analysis indicates that organic materials are especially attractive for low grade heat harvesting under small temperature gradients (e.g., body heat and ambient sources), where flexibility, low mass, and scalable manufacturing may outweigh lower ZT relative to state of the art inorganics. Remaining challenges and research directions are identified such as improving of n type organic performance, long term thermal and chemical stability, and robust, reproducible fabrication.