Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5359132 | Applied Surface Science | 2009 | 4 Pages |
Abstract
Arrays of metal nanoparticles with nanometer-scale gaps between the particles is highly interesting for plasmonic field enhancement applications. We report a simple method to fabricate arrays of closely spaced Au particles with inter-particle separation down to 20Â nm. We used extreme ultraviolet interference lithography (EUV-IL) and a mechanical press to fabricate two-dimensional arrays of Au nanoparticles. Lithographically produced particle arrays were modified by hot pressing in a nanoimprint machine and the gap was varied in a range from 50Â nm to below 20Â nm. Optical measurement shows two resonances at 520Â nm and 620Â nm, with the latter gaining strength as the gap is reduced. The experimental and theoretical investigations using a FDTD algorithm demonstrate that the low-energy resonance can be assigned to a collective surface plasmon resonance arising from the strong near-field coupling between the nanoparticles. Surface Enhanced Raman Spectroscopy (SERS) experiments performed on a model molecule (BPE) show a large gain in signal intensity as a result of the reduced gaps between the particles.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
P.K. Sahoo, K. Vogelsang, H. Schift, H.H. Solak,