Controlling the Morphology of PEDOT:PSS Blend Films with Pre-Deposition Solution Composition and Deposition Technique
Controlling the Morphology of PEDOT:PSS Blend Films with Pre-Deposition Solution Composition and Deposition Technique
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DOI：
10.1021/acsapm.1c00748
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发表时间：
2021-12-08
影响因子：
5
通讯作者：
Dadmun, Mark
中科院分区：
文献类型：
--
作者：
Heroux, Luke;Moncada, Josh;Dadmun, Mark
了解导电聚合物的形态、制造工艺和热电性能之间的关系对于开发高效有机热电材料作为常用稀有金属的替代品至关重要。通过向预制溶液中添加高沸点溶剂来改变聚（3，4-亚乙基二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT：PSS）的膜制造工艺，提高了电导率并显著增加了其塞贝克值。中子散射监测PEDOT：PSS薄膜的原子，纳米级和介观形态的变化与二甲基亚砜（DMSO）的水溶液中加入薄膜形成之前，并与不同的制造程序。中子散射结果表明，随着向预沉积溶液中加入DMSO，最终共混物膜中PEDOT原纤维组装体的系统变化，氘代PSS畴尺寸沿着减小。这些结构修饰表明，文献中报道的添加DMSO的PEDOT：PSS共混物的电导率增加可归因于DMSO对溶剂化PEDOT组装体的破坏，在预沉积溶液中形成较小的PSS域并允许更平滑的膜形成。在仅添加1%DMSO的情况下观察到这些改善显著，但在向PEDOT：PSS共混物预沉积溶液中添加至多5%DMSO的情况下继续适度改善。所测量的形态的变化是独立的膜是否通过旋转或超声喷涂方法沉积的事实强调了在确定最终的薄膜共混物形态的预沉积溶液中的共混物的结构的至关重要性。
Understanding the relationships between morphology, fabrication processes, and thermoelectric performance in conducting polymers is essential to the development of high- efficiency organic thermoelectrics as an alternative to commonly used rare metals. Altering the film fabrication process of poly(3,4-ethylenedioxythiophene):poly-(styrene sulfonate) (PEDOT:PSS) with the addition of high boiling solvents to the precast solution improves the electrical conductivity and significantly increases its Seebeck value. Neutron scattering monitors the changes in the atomic, nanoscale, and mesoscale morphologies of PEDOT:PSS thin films with the addition of dimethyl sulfoxide (DMSO) to the aqueous solution prior to film formation and with varying fabrication procedures. The neutron scattering results show a decrease in the deuterated PSS domain size along with systematic variations in PEDOT fibril assemblies in the final blend film with the addition of DMSO to the pre-deposition solution. These structural modifications indicate that the increase in conductivity of PEDOT:PSS blends with addition of DMSO reported in the literature can be ascribed to the disruption of solvated PEDOT assemblies by the DMSO, forming smaller PSS domains in the pre-deposition solution and allowing smoother film formation. These improvements are observed significantly with the addition of just 1% DMSO but continue to modestly improve with the addition of up to 5% DMSO to the PEDOT:PSS blend pre-deposition solution. The fact that the variations in the measured morphology are independent of whether the films were deposited by spin or ultrasonic spray casting methods emphasizes the crucial importance of the structure of the blend in the pre-deposition solution in determining the final thin film blend morphology.