Jongan Choi  Seohyeon Myeong  Yun-Seok Jun  Seyoung Kee

Vol. 31,  No. 1, pp. 51-57, Mar.  2025
10.7464/ksct.2025.31.1.51

Conducting polymer PEDOT:PSS Ionic liquid Foam Organic thermoelectrics

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The development of organic thermoelectric (TE) materials with three-dimensional structures is essential to meet the growing demand for lightweight, flexible, and efficient energy-harvesting systems in wearable electronics. This study developed poly(3,4- ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) and ionic liquid (IL) composite foams with enhanced TE properties through the incorporation of ethyl-3-methylimidazolium dicyanamide (EMIM DCA) and a freeze-drying process. The electrical conductivity (v) increased by over 1000 times to 19 S cm–1, while the Seebeck coefficient (S) improved by 1.5 times to 26 nV K–1. These increases resulted in a power factor enhancement of over 3,000 times to 1.3 nW m–1 K–2. Scanning electron microscopy revealed larger pore sizes and a well-connected conductive network in the PEDOT:PSS/IL composite foams. The pores and conductive network improved the charge transport and σ. Raman spectroscopy further confirmed the role of EMIM DCA in inducing de-doping effects, thereby enhancing the S of PEDOT:PSS. These findings establish PEDOT:PSS/IL composite foams as promising lightweight and flexible materials for next-generation wearable TE devices because they offer practical solutions for efficient energy-harvesting.