AVS 51st International Symposium
    Nanometer-scale Science and Technology Friday Sessions
       Session NS-FrM

Paper NS-FrM9
Non-Spherical Metal Nanoparticles: Tuning Optical Properties by Controlling Structure

Friday, November 19, 2004, 11:00 am, Room 213D

Session: Nanometer-scale Structures
Presenter: J.S. Shumaker-Parry, Max Planck Institute for Polymer Research, Germany
Authors: J.S. Shumaker-Parry, Max Planck Institute for Polymer Research, Germany
H. Rochholz, Max Planck Institute for Polymer Research, Germany
F. Stefani, Max Planck Institute for Polymer Research, Germany
W. Knoll, Max Planck Institute for Polymer Research, Germany
M. Kreiter, Max Planck Institute for Polymer Research, Germany
Correspondent: Click to Email
Gold colloids have been studied extensively due to the dependence of their optical properties on colloid size, interparticle spacing, and local dielectric environment. Recently there have been efforts to prepare non-spherical nanoparticles because of their unique electronic, optical and other physical properties. We have fabricated novel non-spherical metal nanoparticles by combining colloidal lithography, metal film evaporation and ion beam milling. This process produces a large number of metallic nanoparticles on a surface with uniform size and identical orientation in parallel, a major advantage compared to electron beam lithography methods. Gold and silver quartermoon and c-shaped nanoparticles have been fabricated. A finite element method was applied to classical electrodynamics for two-dimensional models of these nanoparticles in order to understand the optical characteristics. These calculations predict large electromagnetic field enhancements that are localized or uniformly distributed, depending on the nanoparticle structure. We have characterized the optical properties of the nanoparticles using extinction scattering cross section spectroscopy and single-particle light scattering spectroscopy. We show that the optical properties of the nanoparticles can be tuned by changing the size of the colloid mask and by controlling the opening of the c-structure.