Plasmonic Effect of a Nanoshell Dimer with Different Gain Materials

Abstract

Though the plasmonic property for a passive nanoparticle dimer has been studied widely, the performance of a nanoparticle dimer with gain material is still inexplicit to our knowledge. Therefore, in this paper, we focus on the plasmonic effect of a nanoshell dimer, with its core filled with different gain materials, under a polarized plane wave excitation using a three-dimensional finite difference time domain method. It is shown that the gain materials in the core of the nanoshell can compensate the intrinsic absorption of the metal shell, resulting in a local energy enhancement in the junction of the active nanoshell dimer. The physics is supported by the detailed energy distribution of the active nanoshell dimer in each geometry region. It is found that the plasmonic coupling between two active nanoshell particles is more compact than the case of passive ones. The influence of shell thickness on the interaction between two adjacent active nanoshells is also analyzed.

Metallic Nanoshells with Sub-10 nm Thickness and Their Performance as Surface-Enhanced Spectroscopy Substrate

“…The enhancement manifests itself as a localized hot spot in the junction between nanoshells, and its maximum value decreases with the increase of shell thickness. Similar results can be found in previous reports, which show the maximum field enhancement of either single nanoshell or nanoshell dimers decreases with the increase of shell thickness. − So far, there is no specific explanation of this phenomenon. We believe the influence of shell thickness on the field enhancement suggests significant interaction between not only the surface modes but also the cavity modes of neighboring nanoshells.…”

“…Although the plasmon resonance of nanoshells can also be tuned by adjusting the core size, this way greatly influences the damping routes of the surface plasmon (absorption and scattering) and introduces retardation effects. Furthermore, previous theoretical calculations have shown reducing the shell thickness tends to generate larger field enhancements, − which makes great contributions to SES performance. Finally, preparation of continuous ultrathin nanoshell is also cost saving and fundamentally interesting from the viewpoint of nanofabrication.…”

Investigation of the fano lineshapes in plasmonic asymmetric silver nanosphere dimer

“…The extinction spectra of gold nanoparticle dimers, and the electromagnetic contributions to surface-enhanced Raman spectroscopy were calculated by finite element method [14]. The plasmonic effect of a nanoshell dimer, with its core filled with different gain materials, was reported [15]. The plasmonic properties of gold supershape nanoparticle dimers were studied using finite difference time domain simulations, and the resonance wavelength was obtained from extinction spectra for all plasmonic bands [16].…”