Calculation and measurement of radiation corrections for plasmon resonances in nanoparticles

Abstract

The problem of plasmon resonances in metallic nanoparticles can be formulated as an eigenvalue problem under the condition that the wavelengths of the incident radiation are much larger than the particle dimensions. As the nanoparticle size increases, the quasistatic condition is no longer valid. For this reason, the accuracy of the electrostatic approximation may be compromised and appropriate radiation corrections for the calculation of resonance permittivities and resonance wavelengths are needed. In this paper, we present the radiation corrections in the framework of the eigenvalue method for plasmon mode analysis and demonstrate that the computational results accurately match analytical solutions (for nanospheres) and experimental data (for nanorings and nanocubes). We also demonstrate that the optical spectra of silver nanocube suspensions can be fully assigned to dipole-type resonance modes when radiation corrections are introduced. Finally, our method is used to predict the resonance wavelengths for face-to-face silver nanocube dimers on glass substrates. These results may be useful for the indirect measurements of the gaps in the dimers from extinction cross-section observations.

The sodium tungsten bronzes as plasmonic materials: fabrication, calculation and characterization

“…Each of the spectra have been arbitrarily scaled to highlight qualitative trends. In general, increasing the diameter of a nanocube red-shifts the associated LSPRs, as has been reported previously in the literature for the case of Ag [77]. In all of the calculated spectra, an extinction minimum is observed around λ ≈ 450 nm.…”

“…Investigations into the shift of the λLSPR with varying nmedium can be found in the literature for both Au/Ag nanospheres [80][81][82] and nanocubes [72,83,84], which have produced similar numerical values to those presented here. Slight differences in λLSPR in the case of nanocubes can be attributed to edge and corner rounding, which dramatically shift the wavelengths of the corner and edge modes [73,77]. These results have important consequences in chemical sensing applications, which rely on a shift in refractive index with changes in the chemical environment.…”

Enhanced discretization of surface integral equations for resonant scattering analysis of sharp-edged plasmonic nanoparticles

“…Also, we show improved near-field results for the case of a hexahedral silver inclusion computed with our nonconforming implementation and compared to the RWG discretization. The convergence of the resonances of sharp-vertex particles is a particularly interesting example of plasmonic enhancement with a long history [42] used as a test bed for current physics and application-oriented plasmonic research [43][44][45][46][47][48][49][50]. Moreover, the presented methodology could be extended for cases, such as subnano particles and gaps, where enhanced quantum phenomena affect the observed spectrum requiring quantumcorrected classical approaches [51].…”

Light Absorption Enhancement by Employing A Plasmonic Nanobox Cavity Array

“…[1][2][3] The plasmonic nanostructure can be thought as an optical antenna to effectively concentrate the incident electric field and thus significantly enhance large electromagnetic (EM) fields. Plasmon-mediated nanostructures which periodically arranged onto the substrate have the potential to be utilized for a wide range of applications that involve maneuvering the EM spectrum such as light absorbers, 6-8 photovoltaics, 9,10 biochemical sensors, 3,11 metamaterials, 12,13 nano-optical devices, 4 surface-enhanced Raman scattering, [14][15][16] and upconversion luminescence. Plasmon-mediated nanostructures which periodically arranged onto the substrate have the potential to be utilized for a wide range of applications that involve maneuvering the EM spectrum such as light absorbers, 6-8 photovoltaics, 9,10 biochemical sensors, 3,11 metamaterials, 12,13 nano-optical devices, 4 surface-enhanced Raman scattering, [14][15][16] and upconversion luminescence.…”