Constructing Ordered-Structure Organic Thermoelectric Films via Supramolecular Self-Assembly of PEDOT:PSS and Conjugated Triblock Copolymer

Abstract To improve the thermoelectric properties of poly (3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), ordered multilayer-structure films and fiber-structure films were prepared via self-assembly of PEDOT:PSS and aniline tetramer-b-polyethylene glycol-b-aniline tetramer triblock copolymer (APA). Compared to PEDOT:PSS, the multilayer PEDOT:PSS/APA showed stable electrical conductivity and a higher Seebeck coefficient. A maximum power factor of 14.6 μW/(m·K2) was obtained when the mass ratio of PEDOT:PSS to APA was 100:20 at an electrical conductivity of 288 S/cm and a Seebeck coefficient of 21.5μV·K−1, 113% higher than that of PEDOT:PSS. Although the fiber-structure films had relatively low electrical conductivity and Seebeck coefficient, they showed n-type characteristics. The multilayer-structure films and fiber-structure films both have low thermal conductivity, correspondingly, their ZT values are beyond 0.01. The structure tuning of PEDOT:PSS/APA via supramolecular self-assembly between the polymer segments may provide a strategy to develop high performance organic thermoelectric materials.