Luminescence of Dye Molecules in Polymer Films with Plasmonic Nanoparticles

The effect of plasmonic nanoparticles (NPs) on the fluorescence and phosphorescence intensity of organic dye molecules was studied theoretically and experimentally. A theoretical model that takes into account nonradiative transfer of excitation energy from a molecule to an NP and the changes in the rates of spontaneous emission and light absorption by a molecule near an NP was proposed to calculate the luminescence intensity of a molecule in the presence of a plasmonic NP. Numerical estimates for an erythrosine molecule and a silver NP showed that the greatest increase in luminescence was observed at distances of 4–8 nm between the molecule and the NP surface. Experimentally observed changes in luminescence spectra and shortening of the erythrosine triplet state lifetime in poly(vinyl alcohol) films doped with silver NPs were explained using the proposed model.