Ionic liquid (IL) post-treatment of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) thin films with ethyl-3-methylimidazolium dicyanamide (EMIM DCA), allyl-3-methylimidazolium dicyanamide (AMIM DCA), and 1-ethyl-3-methylimidazolium tetracyanoborate (EMIM TCB) is compared. Doping level modifications of PEDOT are characterized using UV–Vis spectroscopy and directly correlate with the observed Seebeck coefficient enhancement. With conductive atomic force microscopy (c-AFM) the authors investigate changes in the topographic-current features of the PEDOT:PSS thin film surface due to IL treatment. Grazing incidence small-angle X-ray scattering (GISAXS) demonstrates the morphological rearrangement towards an optimized PEDOT domain distribution upon IL post-treatment, directly facilitating the interconductivity and causing an increased film conductivity. Based on these improvements in Seebeck coefficient and conductivity, the power factor is increased up to 236 µW m⁻¹K⁻². Subsequently, a model is developed indicating that ILs, which contain small, sterically unhindered ions with a strong localized charge, appear beneficial to boost the thermoelectric performance of post-treated PEDOT:PSS films.

中文翻译：

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离子液体后处理的 PEDOT:PSS 薄膜热电性能、畴形态和掺杂水平的相关性

离子液体 (IL) 后处理聚 (3,4-乙烯二氧噻吩): 聚 (苯乙烯磺酸盐) (PEDOT:PSS) 薄膜与乙基-3-甲基咪唑二氰胺 (EMIM DCA)、烯丙基-3-甲基咪唑二氰胺 ( AMIM DCA) 和 1-乙基-3-甲基咪唑鎓四氰基硼酸盐 (EMIM TCB) 进行了比较。PEDOT 的掺杂水平修改使用 UV-Vis 光谱进行表征，并与观察到的塞贝克系数增强直接相关。作者使用导电原子力显微镜 (c-AFM) 研究了由于 IL 处理导致的 PEDOT:PSS 薄膜表面的形貌电流特征的变化。掠入射小角 X 射线散射 (GISAXS) 展示了 IL 后处理后向优化的 PEDOT 域分布的形态重排，直接促进互导性并导致增加的薄膜电导率。基于塞贝克系数和电导率的这些改进，功率因数增加到 236 µW m^-1 K ^{- 2}。随后，开发了一个模型，表明包含具有强局部电荷的小空间无阻碍离子的 IL 似乎有利于提高后处理 PEDOT:PSS 薄膜的热电性能。