Free-standing highly conducting PEDOT films for flexible thermoelectric generator

Abstract Recently, organic thermoelectric (TE) materials especially conducting polymers have attracted increasing attention. In this work, we successfully synthesized ultrafine poly (3,4-ethylenedioxythiophene) (PEDOT) nanowires (NWs) (∼10 nm) by a simple self-assembled micellar soft-template method and then obtain highly flexible free-standing PEDOT NW films by vacuum-assisted filtration. The films are with very high electrical conductivity (∼1340 S cm−1). After being treated with 6 M H2SO4 and then with 1 M NaOH at room temperature, the film shows an enhanced power factor of 46.51 μW m−1K−2 (Seebeck coefficient of 25.5 μV K−1, electrical conductivity of 715.3 S cm−1), which increases by 54% compared with that of the pristine film. To the best of our knowledge, it outperforms the TE performance of all reported one dimensional conducting polymer-based films. In addition, the TE performance of the film almost remains unchanged even after being bent for 200 times, indicating excellent flexibility. A flexible TE prototype composed of six strips (7 mm × 30 mm) of the as-prepared PEDOT NW films connected in series shows an output power of 157.2 nW at a temperature difference of 51.6 K. The free-standing PEDOT NW films show promise to a new generation of wearable TE devices.