Skip to main content
Article thumbnail
Location of Repository

Optical properties of spherical and oblate spheroidal gold shell colloids

By J.J. Penninkhof, A. Moroz, A. van Blaaderen and A. Polman

Abstract

The surface plasmon modes of spherical and oblate spheroidal core−shell colloids composed of a 312 nm diameter silica core and a 20 nm thick Au shell are investigated. Large arrays of uniaxially aligned core−shell colloids with size aspect ratios ranging from 1.0 to 1.7 are fabricated using a novel ion irradiation technique. Angle- and polarization-resolved extinction spectroscopy is performed on the arrays. Extinction spectra on spherical particles reveal dipole, quadrupole, and octupole resonances in good agreement with calculations using Mie theory. Optical extinction measurements on oblate spheroidal core−shell show strong red- and blue-shifts for polarizations along major and minor axes, respectively, that increase with size anisotropy. The measured spectral shifts of the dipole, quadrupole, and octupole resonant modes with angle and anisotropy are in good agreement with T-matrix calculations. The data provide insight into the tunable resonant behavior of surface plasmons in oblate spheroidal core−shell particles

Year: 2008
OAI identifier: oai:dspace.library.uu.nl:1874/32485
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://dspace.library.uu.nl:80... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.