The Polymer Society of Korea

Abstract

The properties of conductive polymers can be tuned by controlling the charge carrier concentration in their π-conjugated backbones. Oxidation or reduction introduces holes or electrons that enhance electrical conductivity. However, increased doping also alters the electronic structure and energy distribution, causing a trade-off with thermoelectric performance. Thus, doping is a critical parameter for balancing charge transport and functional properties in conductive polymers.
In this study, we investigated the correlation between the doping level and thermoelectric properties of the conductive polymer (PEDOT:PSS) using an OECT-based device architecture. By employing an ionic conductive layer that consist of ionic liquid and polymer matrix as the medium for electrolyte gating, we achieved precise, reversible control over the doping state of the PEDOT:PSS channel. This approach allowed us to measure and analyze changes in the thermal open-circuit voltage (Voc), ultimately elucidating the fundamental relationship between doping concentration and thermoelectric performance.