In this CAREER project, supported by the Chemical Structure, Dynamics and Mechanisms Program of the Chemistry Division, Prof. Michael Tauber of the University of California at San Diego will probe singlet fission in assemblies of carotenoids and perylene diimide dyes. Singlet fission is a process whereby a singlet excited state forms two triplet excited states on neighboring chromophores. Much remains unknown about the mechanism of fission, including the effect of intermolecular coupling on the triplet yield. The project will explore the relationship between fission and the coupling between chromophores, via studies of self-assembled organic chromophores in solution and in the lipid bilayers of vesicles. The techniques for probing the excited-state dynamics include time-resolved and steady-state vibrational and electronic spectroscopy. These studies will lead to an understanding of singlet fission that allows prediction of rates and yields, and elucidate the role of fission in the context of competing excited-state processes.
Results from the five-year project will help scientists assess whether fission can be used to improve the efficiency of new solar cells. The study will also elucidate whether fission serves a functional role in plant photoprotection, which could have an impact on the efficient generation of biofuels from sunlight. Graduate and undergraduate students involved in the project will be broadly trained in topics such as physical chemistry of self-assembly, photophysics, and vibrational/electronic spectroscopy. Also, through a hands-on outreach demonstration with dye-sensitized solar cells, students will have opportunities to educate the public about research in physical chemistry and about NSF-funded activity at UC San Diego that contributes to the development of new sources of efficient and clean energy.
