https://doi.org/10.1140/epjd/e2005-00138-1
Tuning the surface plasmon resonance by preparation of gold-core/silver-shell and alloy nanoparticles
Institut für Physik and Center for
Interdisciplinary Nanostructure Science and Technology — CINSaT,
Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel,
Germany
Corresponding author: a hubentha@physik.uni-kassel.de
Received:
6
September
2004
Published online:
13
July
2005
For many applications
like surface enhanced Raman scattering or fluorescence microscopy
in which the optical field enhancement associated with surface
plasmon excitation is exploited, tunability of this collective
resonance over a wide energy range is required. For this purpose
we have investigated Au/Ag alloyed and Au-core/Ag-shell
nanoparticles with different shell thicknesses. The core-shell
nanoparticles were prepared by subsequent deposition of Au and Ag
atoms on quartz substrates followed by diffusion and nucleation.
The surface plasmon frequency could be stabilized at 2.2 eV
independent of the Ag-shell thickness. Annealing of the core-shell
nanoparticles makes possible tuning of the resonance frequency
from 2.2 eV (
nm) to 2.6 eV (
nm).
Theoretical modelling allows us to attribute this observation to
the formation of alloy nanoparticles.
PACS: 71.45.Gm – Exchange, correlation, dielectric and magnetic response functions, plasmons / 61.46.+w – Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005
