Dielectric Function for Gold in Plasmonics Applications: Size Dependence of Plasmon Resonance Frequencies and Damping Rates for Nanospheres

Abstract

Realistic representation of the frequency dependence of dielectric function of noble metals has a significant impact on the accuracy of description of their optical properties and farther applications in plasmonics, nanoscience, and nanotechnology. Drude-type models successfully used in describing material properties of silver, for gold are known to be not perfect above the threshold energy at 1.8 eV. We give the improved, simple dielectric function for gold which accounts for the frequency dependence of the interband transitions over 1.8 eV and, in addition, for the finite size effects in gold nanoparticles. On that basis, we provide the improved characterization of the spectral performance of gold nanoparticles. Furthermore, we give the direct size dependence of the resonance frequencies and total damping rates of localized surface plasmons of gold nanoparticles (retardation effects are taken into full account) in diverse dielectric environments. The results are compared to the data obtained experimentally for gold monodisperse colloidal nanospheres, as well with the experimental results of other authors.

Exploring the Optical and Morphological Properties of Ag and Ag/TiO2 Nanocomposites Grown by Supersonic Cluster Beam Deposition

“…The bulk-like terms need to be corrected by introducing the FPE term Γ ( R ), which accounts also for the effective reduction in the relaxation time τ in the Drude model when electron mean free path is comparable or larger than NP size [34,43]. …”

Probing nonlocal effects in metals with graphene plasmons

“…Figure 3(a) also shows that an increment of the spacer thickness induces a blueshift in the dispersion relation of the plasmonic modes. For that reason, a naïve approach to account for nonlocal effects while carrying out a local calculation is to consider an effective spacer thickness, s eff , larger than the actual value, s, in a similar fashion to what has been proposed in earlier works [44,47,48]. Although this method can indeed be regarded as a somewhat naïve version of quantum-corrected boundary conditions [49,50], it can mimic the proper nonlocal calculation as illustrated in Fig.…”

Gap‐Mode Plasmon‐Induced Photovoltaic Effect in a Vertical Multilayer Graphene Homojunction

“…The dielectric functions of Au, Ag, and Al for the top electrode were taken from Palik and Johnson data . In case of Au for Au‐NP, the Lorentz‐Drude model was used with size‐dependent collision frequency . The dielectric function of MLG was assumed to be equivalent to a single graphene layer, which was modeled as an anisotropic thin layer ( t = 0.34 nm) having in‐plane permittivity of .…”

“…[29,30] In case of Au for Au-NP, the Lorentz-Drude model was used with size-dependent collision frequency. [31] The dielectric function of MLG was assumed to be equivalent to a single graphene layer, which was modeled as an anisotropic thin layer (t = 0.34 nm) having in-plane permittivity of . The optical conductivity of graphene σ was calculated by random phase approximation.…”