Rahman Md Mahmudur, Solis-de la Fuente Mauricio, Márquez-García Lourdes, Castro-Ruiz Sergio, Liautaud Estelle, Fournier Lucie, Chatard Camille, Bouvet-Marchand Agathe, Culebras Mario, García-Cañadas Jorge
Department of Industrial Systems Engineering and Design, Universitat Jaume I, Castelló de la Plana, Valencian Community, 12006, Spain.
Specific Polymers, Castries, 34160, France.
Open Res Eur. 2025 Aug 4;5:214. doi: 10.12688/openreseurope.20654.1. eCollection 2025.
Thermoelectric (TE) materials can directly convert heat into electricity, which is beneficial for energy sustainability. Organic conducting polymers are TE materials that have drawn significant attention owing to different favorable properties, such as good processability, availability, flexibility, and intrinsically low thermal conductivity. Among the organic TEs, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is the most extensively investigated material because of its stability and high electrical conductivity. The power factor ( ) of PEDOT:PSS can be increased using different strategies, such as secondary doping, dedoping, energy filtering, and sequential post-treatments. All these strategies involve the contact of the polymer with different compounds.
Herein, we have analyzed the impact on the of the treatment of PEDOT:PSS with two different systems: (i) a 0.1M solution of 4,4'-bipyridine in 3-methoxypropionitrile and (ii) a 0.1M solution of LiBF in the same solvent. Impedance, Raman, and ultraviolet-visible-near infrared spectroscopies were employed to understand the variations observed.
The results show that after the treatments, the Seebeck coefficient increased from ca. 12 to ca. 21 μV/K in both cases, and the electrical resistance of the film increased by 46.78% for 4,4'-bipyridine, and only 4.38% in the case of LiBF , reaching at least 2.08 and 3.53 times improvements, respectively, with respect to the initial value (6.32 μWK m ). The impedance spectroscopy analysis revealed that only an ohmic behavior existed in all cases. In addition, Raman and UV-vis-NIR analyses identified a dedoping mechanism, which explains the Seebeck coefficient variations identified in both treatments and the increase in electrical resistance for 4,4'-bypiridine. The remarkable lack of resistance increase for LiBF points to a different phenomenon that could be related to morphological effects.
These two new treatments demonstrate their capability to reach values close to the state of the art and expand the catalogue of treatments available for PEDOT:PSS.
热电（TE）材料可直接将热能转化为电能，这对能源可持续性有益。有机导电聚合物是一类热电材料，因其具有良好的加工性能、可得性、柔韧性以及固有的低导热性等不同的优良特性而备受关注。在有机热电材料中，聚（3,4 - 乙撑二氧噻吩）：聚苯乙烯磺酸盐（PEDOT:PSS）因其稳定性和高导电性而成为研究最为广泛的材料。PEDOT:PSS的功率因数（ ）可通过不同策略提高，如二次掺杂、去掺杂、能量过滤和顺序后处理等。所有这些策略都涉及聚合物与不同化合物的接触。
在此，我们分析了用两种不同体系处理PEDOT:PSS对 的影响：（i）4,4'-联吡啶在3 - 甲氧基丙腈中的0.1M溶液，以及（ii）LiBF 在同一溶剂中的0.1M溶液。采用阻抗、拉曼和紫外 - 可见 - 近红外光谱来理解所观察到的变化。
结果表明，处理后，两种情况下塞贝克系数均从约12 μV/K增加到约21 μV/K，薄膜的电阻对于4,4'-联吡啶增加了46.78%，而对于LiBF 仅增加了4.38%，相对于初始 值（6.32 μWK m ）分别至少提高了2.08倍和3.53倍。阻抗谱分析表明所有情况下仅存在欧姆行为。此外，拉曼和紫外 - 可见 - 近红外分析确定了一种去掺杂机制，这解释了两种处理中所确定的塞贝克系数变化以及4,4'-联吡啶的电阻增加。LiBF 显著缺乏电阻增加表明可能存在与形态效应相关的不同现象。
这两种新处理方法证明了它们能够达到接近现有技术水平的 值，并扩展了可用于PEDOT:PSS的处理方法目录。
