Self-Standing and Flexible Thermoelectric Nanofiber Mat of an n‑Type Conjugated Polymer

The intrinsic flexibility makes conjugated polymers an ideal choice for wearable thermoelectrics. The n-type polymer thermoelectric is still in its infancy. The majority of research on the n-type polymer thermoelectric focuses on the design of n-type conjugated polymers and high-efficiency n-dopants. In this paper, we report a self-standing and flexible nanofiber mat of an n-type conjugate polymer prepared with electrospinning technology. We choose a representative n-type conjugate polymer N2200. The electrospun N2200 nanofiber mat shows a maximal conductivity of 7.06 × 10–4 S/cm, a maximal Seebeck coefficient of −346 μV/K, and a maximal power factor of 0.0085 μW/(m K2). This thermoelectric performance is fairly comparable to that of the traditional spin-coated N2200 thin film. The nanofiber mat is self-standing, flexible, and stretchable and thus can attach to human skin and move with body movement. This work demonstrates the feasibility of fabricating flexible thermoelectric devices by an electrospinning technique and lays a foundation for the applications of n-type conjugated polymers in wearable electronics.