International Collaboration in Chemistry: Novel Approaches to Molecular Assembly in Polymers for Solar Energy Conversion

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

In this International Collaboration in Chemistry between US Investigators and their Counterparts Abroad (ICC) project funded by the Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division and the Office of International Science and Engineering, Michael Chabynic and Craig Hawker of the University of California at Santa Barbara will synthesize hole and electron transporting polymers that can be utilized in nanoimprint lithography to form layers for organic photovoltaic devices. The approach is to synthesize poly(alkyl selenophene)s and copolymers of poly(cyclopenta-dithiophene) with poly(benzothiadiazole) containing thermal and photo-crosslinkable side groups, and these donor polymers will be examined for use in nanoimprint lithography. Next, novel poly(benzotrithiophene) donor polymers and fused thiazole and selenazole acceptor polymers will be prepared and studied. Conformal parylene C coatings will be stacked onto the nanoimprinted donor polymer layer before the double imprint of the acceptor polymer is deposited. Additionally, non-crystalline dyes will be added to the donor layer that should migrate to the surface upon annealing of the donor layer in the imprinting process. These interfacial layers should help to reduce the kinetics of back electron transfer during the charge separation step. This work includes an international collaboration with Prof. Martin Heeney and Prof. Iain McCulloch of the Imperial College London, U.K. Profs. Heeney's and McCulloch's work will be funded by the Engineering and Physical Sciences Research Council (EPSRC). The broader impacts involve training graduate students and enhancing infrastructure for research and education through establishment of an international collaboration between universities in the U.S. and the U.K. The collaborators will endeavor to develop course materials on organic electronics that can be used in the curricula at both universities. Organic polymer-based solar cells show great technological promise but have significant drawbacks in terms of low efficiencies and significant processing problems. This research will enhance our fundamental understanding about how organic polymers can be used to form solar cells and capture light and turn it into electrical energy. By exploring new types of polymers, this research could lead to easier to process and less expensive solar cell technologies.