Effect of nonlocal metal–dielectric environments on concentration quenching of HITC dye

Abstract

Understanding and harnessing energy transfer in organic and inorganic systems is of high fundamental and practical importance. In this work, we have experimentally studied the effect of lamellar hyperbolic metamaterials and metal/dielectric interfaces on the concentration-dependent luminescence quenching in thin polymeric poly (methyl methacrylate) films doped with 2-[7-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)-1,3,5-heptatrienyl]-1,3,3-trimethyl-3H-indoliumiodide dye molecules. The rate of the concentration quenching (energy transfer to quenching centers) was found to be approximately proportional to the square of the dye concentration. The concentration quenching was strongly inhibited in the vicinity of metallic films and lamellar metal–dielectric metamaterials with hyperbolic dispersion. The characteristic length-scale of the inhibition (the distance between the dye molecules and the metallic surface, at which the inhibition becomes significant) was found to be $\sim{47}\,\,{\rm nm}$∼47nm. It was much longer than the Forster radius (the characteristic distance of the donor–acceptor energy transfer, 5 nm to 7 nm), and smaller than the penetration of the surface plasmon polariton field to the dielectric ($ \ge {250}\,\,{\rm nm}$≥250nm). The explanation of the observed phenomenon is likely to be sought in terms of a model taking into account spectral overlap of the emission of donors and absorption of acceptors and/or collective behavior of emitters coupled with surface plasmons.