Nanogap effects on plasmonic properties of dimer

In the field of plasmonics, the nanogap effect is often related to one aspect like the far-field resonance shift or near-field enhancement. In this study, we present a details analysis of the nanogap effect on plasmonic behaviours of the magneto-plasmonic dimer Ni-Ag and Ni-Au nanoparticles by taking the full advantages of DDA simulation. The sets of non-spherical dimer nanostructure viz. edge-to-edge (EE) and face-to-face (FF) and spherical dimer nanoparticles for plasmonic properties like LSPR peak position's tunability as well as peak intensity at the maximum wavelength (lambda(max.)) and near-field enhancement in Ni-Ag and Ni-Au heterodimer nanoparticles is studied. It is observed that the emerging spectra are found between the UV-visible regions (357-586 nm) for spherical dimer nanostructure while prolate dimers are in the UV-visible-Near Infrared region (345-817 nm) under both EE and FF configurations. The emergent wavelength-dependent spectra with varying nanogap between the dimer are red-shifted. The maximum plasmonic field enhancement is observed for Ni-Ag as compared to Ni-Au dimer nanoparticles under spherical and prolate geometry. It is found that the FF configuration of Ni-Ag and Ni-Au dimers nanoparticles has maximum field enhancement in comparison to the EE configuration. These results could have a big impact on how surface-enhanced spectroscopies and related plasmonic instruments based on E-field hot spots or intensity are being utilized.

Automated summary

In this study, the nanogap effect on plasmonic behaviors of magneto-plasmonic dimer nanoparticles was analyzed using DDA simulation. The results showed that the nanogap variation caused a redshift in the emitted wavelength, and the nanoparticles in edge-to-edge configuration exhibited higher field enhancement.