Plasmon-enhanced luminescence of rare-earth ions by gold and silver nanoparticles in PMMA

Abstract

In this work plasmon resonances in gold and silver nanoparticles to enhance luminescent properties of PMMA doped with different rare-earth ions densities are investigated. For this purpose, a rate equation model based on the Förster theory is used. This model describes the luminescent dynamics between donor and acceptor rare earth ions and considers the electric field changes due to metallic nanoparticles. The MNPBEM Matlab toolbox is used to calculate the electric field in our system, including the electric field of the excitation and the electric field induced by the nanoparticle. The results show that rare earth luminescence can be increased in the proximity of spherical gold and silver nanoparticles due to the change in the optical field and the transition rates. Accordingly, the rate equation model proposed here explains the increase in luminescent emission when the dopants interact with the metal nanoparticles. Additionally, the calculations allow to find the optimal conditions of nanoparticle size and excitation wavelength to achieve the maximum amplification of optical field and, therefore, the maximum amplification of the emission of rare earth ions.