Angle- and Energy-Resolved Plasmon Coupling in Gold Nanorod Dimers

Abstract

The plasmon coupling in the dimers of Au nanorods linked together at their ends with dithiol molecules has been studied. The plasmon coupling in the dimers composed of similarly sized nanorods gives antibonding and bonding plasmon modes. The plasmon wavelengths of the two modes have been found to remain approximately unchanged, with the scattering intensity ratio between the antibonding and bonding modes decaying rapidly as the angle between the nanorods is increased. This plasmon coupling behavior agrees with that obtained from both electrodynamic calculations and modeling on the basis of the dipole-dipole interaction. The electric field in the gap region is largely enhanced for the bonding mode, while that for the antibonding mode is even smaller than the far field, highlighting the importance of selecting appropriate plasmon modes for plasmon-enhanced spectroscopies. An anti-crossing-like behavior in the plasmon coupling energy diagram has further been revealed for linearly end-to-end assembled dimers composed of differently sized nanorods. This result will be useful for plasmonic applications where the plasmon wavelength is required to be controllable but without sacrificing the electric field enhancement.

Optimal Polarization Conversion in Coupled Dimer Plasmonic Nanoantennas for Metasurfaces

“…12,15,16 The above studies all considered connected antenna designs; disconnected nanorod dimers in an orthogonal geometry were explored in Refs. [19][20][21]. Similar to the case of aligned nanoparticle dimers, 22,23 the nature of the interactions between disconnected and connected rods is qualitatively different.…”

Hollow metal nanostructures for enhanced plasmonics: synthesis, local plasmonic properties and applications

“…The most common and simplistic case of plasmon hybridization is a dimer of two closely located nanostructures [21], and the term is widely used to explain the interaction between two solid nanostructures or the interaction between the nanostructure and the environment, i.e. the substrate [22][23][24][25][26][27][28][29][30][31][32][33][34][35]. In this review, we will focus on the plasmon hybridization in hollow nanostructures [13,20,[36][37][38][39][40].…”

Manipulating and probing the growth of plasmonic nanoparticle arrays using light

“…5 A wide range of applications is possible as the plasmonic properties of metal NPs can be tuned by changing their size and shape. 6 Particular interest has been focused in the area of coupled NPs 7,8 as they provide more flexibility and advanced functionalities. Coupled NP arrays have been used as building blocks for wave guides [9][10][11] and to increase solar cell efficiency.…”