Collaborative Research: Using Conjugated Polymer Brushes to Control Interfacial Properties and Morphology of Polymer Solar Cells

在这个由化学系大分子、超分子和纳米化学计划资助的项目中，北卡罗来纳大学教堂山分校的魏友和佐治亚大学的Jason Locklin将探索表面引发可控聚合的化学方法，以解决在有机光伏电池中更换聚苯乙烯磺酸盐-聚(2，4-乙二氧基噻吩基)/铟-锡氧化层的问题。方法是研究表面和溶液中噻吩类Kumada偶联聚合的机理，以找出合适的条件从表面控制聚噻吩刷的生长，将这一化学扩展到噻吩噻唑单体，然后利用各种薄膜表征技术和器件结构来探索电极上这些活性层的界面性质和形貌。共轭聚合物电刷作为界面层可以提供均匀的薄膜，具有均匀的厚度；改善了电极和有源层之间的接触性能；并减少了电荷注入的障碍。更广泛的影响包括通过合作对本科生和研究生研究人员进行跨学科培训，将这些研究概念整合到有机电子和软材料课程中，并参与面向未被充分代表的少数民族、高中生和普通公众的外联活动。这项工作将加深我们对导电聚合物薄膜的合成及其光化学行为的基本理解。最终，这些工作可能会导致有机电子材料、低成本太阳能电池、发光显示器以及化学和生物传感器的发展。

In this project funded by the Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division, Wei You of University of North Carolina at Chapel Hill and Jason Locklin of University of Georgia will explore chemistry for the controlled surface-initiated polymerization of thiophene in order to solve the problem of replacing polystyrene sulfonate - poly(2,4-ethylenedioxythiophene) / indium-tin-oxide layers in organic photovoltaic cells. The approach is to study the mechanism of Kumada-type coupling polymerizations of thiophene in solution and from surfaces in order to uncover the proper conditions for controlled growth of polythiophene brushes from surfaces, to extend this chemistry to thienothiazole monomers, and then to probe the interfacial properties and morphologies of these active layers on electrodes using a variety of thin film characterization techniques and device architectures. Conjugated polymer brushes as the interfacial layer may offer a homogeneous film with uniform thickness; improved contact properties between the electrode and the active layer; and reduced barriers to charge injection. The broader impacts involve interdisciplinary training of undergraduate and graduate student researchers via the collaboration, integrating these research concepts into courses on organic electronics and soft materials, and participating in outreach activities to underrepresented minorities, high school students, and the general public.This work will enhance our fundamental understanding about synthesizing thin films of conducting polymers and their photochemical behavior. Ultimately, such work could lead to the development of organic electronic materials, low cost solar cells, light emitting displays, and chemical and biological sensors.