Tunable optical properties of gold semi-shell nanoparicles

Abstract

The optical properties of gold semi-shell nanopartilces with different shell thicknesses, geometrical morphology and physical parameters are theoretically studied by discrete dipole approximation method. The numerical results show that the extinction resonance wavelength of semi-shell nanoparticle is first blue-shifted and then red-shifted as the shell thickness increases, the shell thickness corresponding to resonance wavelength shifting to opposite direction increases with the increase of aspect ratio, and with the increase of dielectric constants of the inner core material and the embedding medium. The shift of the resonance wavelength is ascribed to the mutual interactions between plasmon hybridization and phase retardation. The plasmon hybridization plays an important role as the shell thickness is thin, as the shell thickness get thicker, phase retardation effect will become significant.