Flexible thermoelectric nanodevices based on three-dimensional networks of poly(3,4-ethylenedioxythiophene) nanowires and graphene

Abstract

Freestanding poly(3,4-ethylenedioxythiophene) (PEDOT) nanowires (NWs) were synthesized using a facile, self-assembled, micellar soft-template method. Thermoelectric properties of the PEDOT NWs under different reaction conditions were measured, and optimal experimental conditions were confirmed. To obtain preferential thermoelectric performance, PEDOT NWs/graphene composite films with various graphene mass fractions were fabricated. The maximum power factor of the hybrids was observed to reach 42.0 μWm−1K−2 with 3 wt% graphene loading, corresponding to a 200% improvement compared with pure PEDOT NWs. The thermoelectric devices were investigated using the PEDOT NWs/graphene hybrids as a p-type leg and PEDOT NWs/nitrogen-doped graphene as an n-type leg. The device, in series, shows a preferable cooling effect with an approximate temperature decrease of 0.5°C after energization. Our work provides a novel means of fabricating n-type PEDOT hybrids and promotes their practical applications as thermoelectric coolers. These findings indicate a new means of developing high-performance, flexible, organic thermoelectric materials and devices.