Molecular and Morphology Engineering of Non-Fullerene Organic Solar Cells

University Of Washington, Seattle WA

Investigators

Abstract

Organic solar photovoltaic cells are promising low cost, scalable, and sustainable solar energy based electrical power generation technologies. Major innovations in semiconductor materials are needed to create energy conversion and energy storage devices based upon organic photovoltaics. This project aims to discover fundamental knowledge needed for creating organic semiconductor materials with improved properties and for designing more efficient organic solar cells. The project develops engineering strategies to design, synthesize, and process new materials with the aim of enhancing how they absorb light, generate charge, and transport charge through thin films and in devices. The project also provides opportunities for training future scientists and engineers, including women and underrepresented minorities in STEM, in the interdisciplinary fields of semiconductor materials, optoelectronic devices, and energy technologies. The project also enables improvements to the curriculum by integration of research findings into the graduate and undergraduate courses taught at the University of Washington. As part of this project, a symposium on solar energy frontier research will be organized for a future American Chemical Society or Materials Research Society meeting. Researchers involved in this project also will participate in a program organized by the Pacific Science Center of Seattle focusing on renewable energy and solar technologies. Photovoltaic devices have generally been made by blending a p-type (donor) semiconducting polymer with an electron-conducting (acceptor) fullerene derivative. This project studies new non-fullerene acceptors that are expected to be more chemically, photochemically and mechanically rugged, more economical, and more readily manufactured on a large scale compared to their fullerene counterparts. The project also involves new morphology engineering approaches for understanding and achieving high performance non-fullerene organic solar cells. The following objectives are being pursued: (1) The design, synthesis, and characterization of a series of cyclopentaquinoxaline-based small-molecule, non-fullerene, acceptor materials; (2) The design, synthesis, and characterization of new amorphous wide bandgap p-type semiconducting copolymers with optimal properties suitable for high performance solar cells; and (3) The investigation of the morphology, photophysics, charge transport, charge recombination and photovoltaic properties of blends of the new acceptor materials with donor polymers. The results of these studies will generate new fundamental understanding of light absorption and charge transport in n-type organic semiconductors and will provide new physical insights into charge photogeneration, transport, and collection in organic solar cells. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.