Flexible Thermoelectric Generator Based on Dip‐Coated SWCNT/PEDOT:PSS Composite Films for High Power Generation

ABSTRACT Single‐walled carbon nanotube (SWCNT) films hold great promise for advancing flexible thermoelectric generators. However, achieving a high power factor for the films as well as device output power remains challenging. Herein, a scalable dip‐coating strategy to fabricate vacuum‐filtered SWCNT films conformally coated with poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is reported. This approach enhances interfacial charge transport and enables precise control over the SWCNT film coating. By optimizing the coating duration, the SWCNT/PEDOT:PSS composite films achieved a power factor of ∼340 µW/mK 2 near room temperature. These values exceed those of pristine SWCNT films by ∼30% and outperform most previously reported films prepared via direct mixing or drop‐casting. To demonstrate practical applicability, five pairs of SWCNT/PEDOT:PSS composite films were integrated onto an Ecoflex substrate to fabricate a flexible thermoelectric generator. The device provided a power density of ∼0.32 µW/cm 2 at a 30 K temperature gradient with stable performance over repeated cycles. The combination of scalability, low‐cost processing, and improved thermoelectric performance highlights dip‐coating as a compelling and versatile route for the development of next‐generation SWCNT‐based flexible thermoelectric generators.