Plasmonics effects in non-touching and nearly touching silver-shell nanospherical dimers
程俊賢1, Yuan-Fong Chau1*
1電子系, 健行科技大學, 中壢, Taiwan
* presenting author:Yuan-Fong Chau,
In this paper, we have investigated the plasmonics effects in no-touching and nearly touching silver-shell nanospherical dimers by means of finite element method in three-dimensional models. The response of non-touching and nearly touching of silver nanoparticle dimers is studied theoretically near and beyond the limit where the particles are touching. It is shown that the non-touching or nearly touching nanoparticles approach each other, a dominant dipole feature is observed that is pushed into the infrared due to interparticle coupling and that is associated with a large accumulation of induced positive and negative charges in the interparticle gap. Note that the redshift becomes singular as the particle separation decreases. The response of non-touching case is weak than that of touching case for very small separation. When the junction is made by contact between flat surfaces, charge at the junction is offseted and mode evolution is continuous through contact. These calculated results are relevant in the design of nanoparticle-based sensors, plasmon circuits and other nanophotonic devices.

Keywords: Plasmonics effects, finite element method , nanoparticle-based sensors