Strong Coupling of Organic Excitons to Surface Lattice Resonances*

We report on the fabrication and spectral characterization of films of dyes and dye-doped polymers deposited on top of 2D periodic arrays of gold nanoparticles. Coupling between the dye excitons and the plasmonic surface lattice resonances (SLRs) of the gold particle arrays is investigated by measurement of angle resolved transmission and reflection spectra, and of photoluminescence spectra and images. These results are analyzed to determine the degree of coupling between the organic excitons and the SLRs of the arrays, and to elucidate the nature of the resulting hybrid states, including their dispersion relations. In addition, the effect of coupling on the rate of energy transfer between spatially separated layers of donor and acceptor dyes is examined to determine if the energy transfer is enhanced, as was observed in donor and acceptor films strongly coupled to an optical microcavity. Finally, coupling between the plasmonic arrays and supramolecular aggregates of dye molecules is also investigated. Based on these results, the potential application of SLR-supporting arrays in organic thin film solar cells is discussed.