Enhanced luminescence of Eu-doped films based on gap coupled plasmons

Abstract

Coupled plasmons are promising candidates for enhancing the luminescence, which can drastically alter the electromagnetic environment of emitters and modulate their emission process. In this paper, we have carried out a comparison of enhanced luminescence based on different plasmonic nanostructures and designed a gap coupled structure Au nanorods (NRs)/space layer/Ag nanoparticles (NPs) film to enhance the photoluminescence (PL) of Eu film. The current result indicates that our maximum enhancement factor is 53.5-fold. And our studies reveal that the Ag NPs film as the substrate provides electromagnetic field enhancement, the space layer as the intermediate layer adjusts the distance to decrease the nonradiative energy transfer. A dominant role of the Au NRs in luminescence enhancement is also indicated due to the perfect match between local surface plasmon resonance (LSPR) of Au NRs and the emission spectrum of Eu. Our designed gap coupled nanostructure has multiple plasmon couplings, which can be beneficial to certain applications such as gap coupled plasmonic nanostructure-based detectors and devices.