Distinguishable Plasmonic Nanoparticle and Gap Mode Properties in a Silver Nanoparticle on a Gold Film System Using Three-Dimensional FDTD Simulations

• Main Authors: Vasanthan Devaraj, Jong-Min Lee, Jin-Woo Oh
• Format: Article
• Language: English
• Published: MDPI AG 2018-07-01
• Series: Nanomaterials
• Subjects: plasmonics; simulations; metallic nanostructures; near-field enhancement; plasmonic modes; particle on a film
• Online Access: http://www.mdpi.com/2079-4991/8/8/582

We present a computational study of the near-field enhancement properties from a plasmonic nanomaterial based on a silver nanoparticle on a gold film. Our simulation studies show a clear distinguishability between nanoparticle mode and gap mode as a function of dielectric layer thickness. The observed nanoparticle mode is independent of dielectric layer thickness, and hence its related plasmonic properties can be investigated clearly by having a minimum of ~10-nm-thick dielectric layer on a metallic film. In case of the gap mode, the presence of minimal dielectric layer thickness is crucial (~≤4 nm), as deterioration starts rapidly thereafter. The proposed simple tunable gap-based particle on film design might open interesting studies in the field of plasmonics, extreme light confinement, sensing, and source enhancement of an emitter.