title: Energy and Electron Transfer Cascade in Self-Assembled Bilayer Dye-Sensitized Solar Cells.
abstract: Current high efficiency dye-sensitized solar cells (DSSCs) rely on the incorporation of multiple chromophores, via either codeposition or preformed assemblies, as a means of increasing broad band light absorption. These strategies have some inherent limitations including decreased total light absorption by each of the dyes, low surface loadings, and complex synthetic procedures. In this report, we introduce an alternative strategy, self-assembled bilayers, as a simple, stepwise method of incorporating two complementary chromophores into a DSSC. The bilayer devices exhibit a 10% increase in Jsc, Voc, and η over the monolayer devices due to increased incident photon-to-electron conversion efficiency across the entire visible spectrum and slowed recombination losses at the interface. Directional energy and electron transfer toward the metal oxide surface are key steps in the bilayer photon-to-current generation process. These results are important as they open the door to a new architecture for harnessing broadband light in dye-sensitized devices.
authors.affiliation: Materials Science and Engineering and ‡Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States.
authors.forename: Omotola O
authors.initials: OO
authors.lastname: Ogunsolu
authors.affiliation: Materials Science and Engineering and ‡Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Murphy
authors.affiliation: Materials Science and Engineering and ‡Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States.
authors.forename: Jamie C
authors.initials: JC
authors.lastname: Wang
authors.affiliation: Materials Science and Engineering and ‡Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States.
authors.forename: Anjan
authors.initials: A
authors.lastname: Das
authors.affiliation: Materials Science and Engineering and ‡Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Hanson
keywords: DSSC; bilayer; electron transfer; energy transfer; self-assembly