Simulated study of plasmonic coupling in noble bimetallic alloy nanosphere arrays

Abstract

The plasmonic coupling between the interacting noble metal nanoparticles plays an important role to influence the optical properties of arrays. In this work, we have extended the Mie theory results of our recent communication to include the effect of particle interactions between the alloy nanoparticles by varying interparticle distance and number of particles. The localized surface plasmon resonance (LSPR) peak position, full width at half maxima (FWHM) and scattering efficiency of one dimensional (1D) bimetallic alloy nanosphere (BANS) arrays of earlier optimized compositions i.e. Ag0.75Au0.25, Au0.25Cu0.75 and Ag0.50Cu0.50 have been studied presently by using discrete dipole approximation (DDA) simulations. Studies have been made to optimize size of the nanosphere, number of spheres in the arrays, material and the interparticle distance. It has been found that both the scattering efficiency and FWHM (bandwidth) can be controlled in the large region of the electromagnetic (EM) spectrum by varying the number of interacting particles and interparticle distance. In comparison to other alloy arrays, Ag0.50Cu0.50 BANS arrays (each of particle radius 50 nm) shows larger tunability of LSPR with wide bandwidth (essential condition for plasmonic solar cells).

Structural defect induced peak splitting in gold–copper bimetallic nanorods during growth by single particle spectroscopy

“…As mentioned above, only one scattering peak was found in single Au nanorods 40,41 , whereas in our experimental study of single Au-Cu alloy nanorods, multiple scattering peaks were observed. This is because that Au and Cu have similar dielectric functions above 550 nm where the resonance wavelengths are located 39,42 . Specifically, since the composition of the nanorods changes gradually during the reaction, we varied the fraction of Au and Cu in a nanorod using their respective dielectric constants for their occupied volumes.…”

Surface plasmon resonance sensor based on bimetallic alloys grating

“…Therefore, when individual metals are combined to form alloys, variations in dielectric constant values [23,24] are responsible for the changes in the SPR peak position and FWHM. When the Au fraction[0.5, a drastic change in the FWHM of Au-Ag-based sensor, as compared to the sensors based on Au-Pt and Au-Pd composition has been Fig.…”

Effect of interparticle plasmon coupling and temperature on the optical properties of bimetallic composite nanoparticles with a core-shell structure

“…Owing to the interparticle plasmon coupling of nanofillers into the composite, a new peak in the plasmonic absorption spectrum is observed because the plasmon resonance of each particle is affected by plasmon resonance of its neighboring particle. 44 On the other hand, a new plasmon oscillation mode is created. The extent of the plasmon shift increases with an increase in the host matrix and environment medium dielectric constant, as well as produces a red-shift of the plasmon band maximum.…”