Metallic nanoparticles are known to enhance nonlinear optical processes due to a local enhancement of the optical field. This strategy has been proposed to enhance downconversion in thin film solar cells, but has various disadvantages, among which is the fact that the enhancement occurs only in a tiny volume close to the particles. We report on a very different physical mechanism that can lead to significant downconversion enhancement, namely, that of resonant light scattering, and which is a large volume effect. We show that only a tiny amount of resonantly scattering metallic (aluminum) nanoparticles is enough to create a significant enhancement of the fluorescence of dye molecules in the visible wavelength range. The strategy can be applied in general to increase the emission of UV-absorbing constituents, and is of particular use for solar energy.
© 2012 Optical Society of America
Original Manuscript: September 28, 2011
Revised Manuscript: November 18, 2011
Manuscript Accepted: November 19, 2011
Published: January 24, 2012
Vol. 7, Iss. 4 Virtual Journal for Biomedical Optics
Rajeshkumar Mupparapu, Kevin Vynck, Iacopo Malfanti, Silvia Vignolini, Matteo Burresi, Petra Scudo, Roberto Fusco, and Diederik S Wiersma, "Enhanced downconversion of UV light by resonant scattering of aluminum nanoparticles," Opt. Lett. 37, 368-370 (2012)