In this project funded by the Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division, Sarah Tolbert, Yves Rubin, and Benjamin Schwartz of the University of California at Los Angeles will develop methods for the solution-phase self-assembly of fullerene derivatives and conjugated polymers into films for organic solar cells. The research has three complementary components. In the first part, the research will focus on the use of molecular assembly in self-complementary fullerene derivatives to optimize network architecture for increased electron mobility. In the second part, carrier mobility in the semiconducting polymer will be examined and optimized, this time using self-assembly of amphiphilic semiconducting polymers in aqueous solution. Finally, to facilitate the use of high mobility electron acceptors such as titania, fullerenes with surface binding groups will be prepared and the performance of solar cells incorporating nanostructured titania covered with fullerene monolayers will be studied. The broader impacts involve training graduate and undergraduate students, enhancing research infrastructure by bringing together a collaborative group, conducting high school teacher workshops on solar cells/solar energy, and the potential societal benefits of inexpensive organic photovoltaic devices.
Solar cells made from electrically conducting plastics show great technological promise but have significant drawbacks in terms of low efficiencies and irreproducibility in processing. This research seeks to solve some of those problems by enhancing our fundamental understanding of how to integrate various organic compounds to capture light and turn it into electrical energy. The specific focus is to find robust ways to create nanometer sized structures that can efficiently generate electricity and then transport that electricity out of the solar cell for usage. Through development of new chemical components and processing strategies, this research could lead to easier to produce and less expensive solar cell technologies.