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.
