Dense Two-Dimensional Silver Single and Double Nanoparticle Arrays with Plasmonic Response in Wide Spectral Range

Abstract

We report the properties of plasmons in dense planar arrays of silver single and double nanostructures with various geometries fabricated by electron beam lithography (EBL) as a function of their size and spacing. We demonstrate a strong plasmon coupling mechanism due to near-field dipolar interactions between adjacent nanostructures, which produces a major red shift of the localized surface plasmon resonance (LSPR) in silver nanoparticles and leads to strong maximum electric field enhancements in a broad spectral range. The extinction spectra and maximum electric field enhancements are theoretically modeled by using the finite element method. Our modeling revealed that strong averaged electric field enhancements of up to 60 in visible range and up to 40 in mid-infrared result from hybridization of multipolar resonances in such dense nanostructures; these are important for applications in surface enhanced spectroscopies.

Surface-plasmon mediated photoluminescence enhancement of Pt-coated ZnO nanowires by inserting an atomic-layer-deposited Al2O3spacer layer

“…The increase of the electron density in the conduction band of ZnO NWs will enhance the NBE emission, as shown in figure 7. It is known that the SPR energy is highly sensitive to the metal particle size and shape, the interparticle spacing, and the dielectric properties of the surrounding medium [50][51][52][53][54]. The metal enhanced electromagnetic field due to the surface plasmons generated at the interface between the metal and dielectric medium is a nearfield effect and will decay exponentially with distance from the metal surface [55,56].…”

Femtomolar Detection of Spermidine Using Au Decorated SiO2 Nanohybrid on Plasmon-Coupled Extended Cavity Nanointerface: A Smartphone-Based Fluorescence Dequenching Approach

“…A variety of shapes and sizes of different coinage metal NPs with hybrid photonic morphologies have been explored to understand their contribution toward MEF . Plasmonic NPs with sharp edges and crevices make allowance for extreme electronic oscillations at such locations. , Further, nanoclusters and nanocomposites have been synthesized and explored to understand the contribution of void plasmons toward local electric-field amplification. − Discrete-dipole approximation (DDA) calculations have confirmed the utility of NP aggregates and multifaceted anisotropic structures to show excellent performance toward MEF . Advancements in MEF technology have been realized through recent developments in surface plasmon resonance (SPR), surface plasmon-coupled emission (SPCE) (including fluorescence (SPCF), , chemiluminescence (SPCC), and phosphorescence (SPCP)), Tamm-state coupled emission (TSCE) and metal-dielectric-metal (MDM) nanointerfaces .…”

“…5 Plasmonic NPs with sharp edges and crevices make allowance for extreme electronic oscillations at such locations. 1,6 Further, nanoclusters and nanocomposites have been synthesized and explored to understand the contribution of void plasmons toward local electric-field amplification. 7−9 Discrete-dipole approximation (DDA) calculations have confirmed the utility of NP aggregates and multifaceted anisotropic structures to show excellent performance toward MEF.…”

Metal-enhanced fluorescence in the life sciences: here, now and beyond

“…Numerous authors, including ourselves, have exploited this phenomenon to design highly efficient MEF substrates. [21][22][23] The locally amplified electric field (E) produces local enhancement of fluorescence, due to the fact that the fluorescence emitted power (P fluorophore ) is proportional to the photon flux which, by its turn, is proportional to the electric field squared, assuming that there is no saturation effect in the excited state: 24…”