Plasmonic Properties of the Metal Nanoparticles (NPs) on a Metal Mirror Separated by an Ultrathin Oxide Layer

The plasmonic resonance frequency of metal nanoparticles (NPs) strongly depend on the geometry, size, and separation between NPs. Here, a structure is designed based film-coupled nanoparticle phenomenon analytically investigated by finite element method via COMSOL Multiphysics software tool. optical behavior studied compared for two noble metals (gold silver as case study). Simulation results confirmed that structural elements such dielectric layer thickness, film distance significantly affect properties. Consequently, optimizing dimensions mentioned in strong field enhancement gap layer. simplicity this structure, easy controlling confinement limited area, lack incident light angle tunning are characteristic features proposed structure. Strong volume makes promising nanoantennas, SERS platforms, sensing applications.