One-step post-treatment with amphoteric salt for simultaneous improvement of Seebeck coefficient and electrical conductivity of PEDOT: PSS thermoelectric films

Continuous acid-base treatment can achieve high thermoelectric performance for PEDOT:PSS film, but multiple surface treatments damage samples easily, lowering yield rates as well as increasing preparation costs, preventing its commercialization. To this end, we present an amphoteric salt-based post-treatment strategy for optimizing the charge transport properties and doping levels of PEDOT:PSS films, thereby achieving high electrical conductivity (σ) and Seebeck coefficient (S) simultaneously. As a result, the optimal PEDOT:PSS thermoelectric film delivers a σ of 1462 S·cm−1 and a S of 26.2 μV·K−1, thus achieving a power factor (PF) of 100.4 μW·m−1·K−2, which is significantly higher than pristine specimens with a PF lower than 0.1 μW·m−1·K−2.