Impact of surface collisions on enhancement and quenching of the luminescence near the metal nanoparticles

TL;DR

This paper investigates how surface collisions and mode confinement in metal nanoparticles increase damping of nonradiative surface plasmon polaritons, leading to enhanced luminescence quenching and reduced luminescence enhancement.

Contribution

It reveals that damping of higher order nonradiative SPP modes is significantly increased by mode confinement, impacting luminescence near metal nanoparticles.

Findings

Higher order SPP mode damping increases with mode confinement.

Luminescence quenching is substantially enhanced near metal surfaces.

Luminescence enhancement is limited by increased damping of nonradiative modes.

Abstract

The fact that surface-induced damping rate of surface plasmon polaritons (SPPs) in metal nanoparticles increases with the decrease of particle size is well known. We show that this rate also increases with the degree of the mode confinement, hence damping of the higher order nonradiative SPP modes in spherical particles is greatly enhanced relative to damping of the fundamental (dipole) SPP mode. Since higher order modes are the ones responsible for quenching of luminescence in the vicinity of metal surfaces, the degree of quenching increases resulting in a substantial decrease in the amount of attainable enhancement of the luminescence