Abstract
We performed single particle deformation experiments on silicacoated gold nanorods under femtosecond (fs) illumination. Changes in the particle shape were analyzed by electron microscopy and associated changes in the plasmon resonance by electron energy loss spectroscopy. Silica-coated rods were found to be more stable compared to uncoated rods but could still be deformed via an intermediate bullet-like shape for silica shell thicknesses of 14 nm. Changes
in the size ratio of the rods after fs-illumination resulted in blue-shifting of the
longitudinal plasmon resonances. Two-dimensional spatial mapping of the
plasmon resonances revealed that the flat side of the bullet-like particles showed
a less pronounced longitudinal plasmonic electric field enhancement. These
findings were confirmed by finite-difference time-domain (FDTD) simulations.
Furthermore, at higher laser fluences size reduction of the particles was found as
well as for particles that were not completely deformed yet.
in the size ratio of the rods after fs-illumination resulted in blue-shifting of the
longitudinal plasmon resonances. Two-dimensional spatial mapping of the
plasmon resonances revealed that the flat side of the bullet-like particles showed
a less pronounced longitudinal plasmonic electric field enhancement. These
findings were confirmed by finite-difference time-domain (FDTD) simulations.
Furthermore, at higher laser fluences size reduction of the particles was found as
well as for particles that were not completely deformed yet.
| Original language | English |
|---|---|
| Pages (from-to) | 1818-1825 |
| Number of pages | 8 |
| Journal | Nano Letters |
| Volume | 16 |
| DOIs | |
| Publication status | Published - 12 Feb 2016 |
Keywords
- Gold nanorods
- femtosecond laser excitation
- deformation
- EELS