Plasmonic nanospheres with a handle-Local electrochemical deposition of Au or Ag at the apex of optically inactive W- or C-tips

摘要

We developed an electrochemical method for the local deposition of spherical particles of plasmonic metals like Au or Ag at the apex of conductive tips. The electrochemical metal deposition was confined to the tip apex by the application of short potential pulses between the tip and a sacrificial electrode in close proximity. The diameter of the deposits could be varied between several 10 nm to about 1 μm. Cathodoluminescence maps of the decorated tips showed enhanced luminescence at the Au or Ag nanospheres. Local cathodoluminescence spectra proved excitation of surface plasmons characteristic for metallic Ag or Au.