POS5-0737
Modulation of Thermoelectric Performance in PEDOT:PSS OECT Using Electrolyte-Gated Doping
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
Sanghee Lee (School of Materials Science & Engineering, Kookmin University)
Co-Author(s)
Abstract
The thermoelectric performance of organic mixed ionic–electronic conductor (OMIEC)-based devices is governed by the complex interplay between ionic thermal diffusion and electronic transport under a temperature gradient. Conventional studies have primarily investigated variations in thermoelectric performance through static compositional modifications, such as modulating the ion concentration within the electrolyte or altering the physical blending ratio of electronically conductive materials. These traditional approaches are inherently limited in capturing the dynamic decoupling of charge carriers in real time. To address this limitation, our study distinguishes itself by utilizing an organic electrochemical transistor (OECT) architecture to measure and analyze long-term thermoelectric property variations in situ as a function of the applied gate voltage (Vg). Through this approach, we aim to decouple and elucidate the complex thermoelectric driving mechanisms and performance variations within OMIEC devices by isolating the distinct contributions of electronic and ionic behaviors. In this work, we investigate the long-term thermoelectric properties of OMIECs under applied Vg. By utilizing an OECT consisting of a PEDOT:PSS channel and an ionogel electrolyte, we aim to decouple the thermoelectric driving mechanisms into distinct electronic and ionic behaviors.
Furthermore, to elucidate the underlying thermoelectric mechanisms, we analyzed in-situ open-circuit voltage (Voc) profiles under the thermal gradient. Based on Joule heating on/off cycles, we propose a comprehensive five-stage model: (I) initial carrier migration driven by the Soret and Seebeck effects, (II) interfacial charge compensation between accumulated ions and electronic carriers, (III) charge equilibrium sustaining a net thermo-voltage, (IV) thermal dissipation upon heater deactivation, and (V) charge neutralization that returns the system to its initial state.
Furthermore, to elucidate the underlying thermoelectric mechanisms, we analyzed in-situ open-circuit voltage (Voc) profiles under the thermal gradient. Based on Joule heating on/off cycles, we propose a comprehensive five-stage model: (I) initial carrier migration driven by the Soret and Seebeck effects, (II) interfacial charge compensation between accumulated ions and electronic carriers, (III) charge equilibrium sustaining a net thermo-voltage, (IV) thermal dissipation upon heater deactivation, and (V) charge neutralization that returns the system to its initial state.
