An effective approach to enhanced thermoelectric properties of PEDOT:PSS films by a DES post-treatment

As conventional organic solvents present inherent toxicity, deep eutectic solvents (DES) have been considered as excellent candidates due to their green characteristics. In this work, thermoelectric properties enhancement of PEDOT:PSS films is achieved by introducing DES as an additive and post-treatment reagent. Direct addition and post-treatment approaches lead to a maximum Seebeck coefficient of 29.1 μV K−1 and electrical conductivity of 620.6 S cm−1, respectively. In addition, an optimal power factor is obtained by DES post-treatment, reaching up to 24.08 μW m−1 K−2, which is approximately four orders of magnitude higher than the pure PEDOT:PSS. Assuming a thermal conductivity of 0.17 W m−1 K−1, the maximum ZT value is estimated to be 0.042 at 300 K. Further, atomic force microscopy and X-ray photoelectron spectroscopy are performed and suggest that the remarkably enhanced electrical conductivity originates from the removal of the excess insulating PSS and the phase separation between the PEDOT and PSS chains. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 885–892