title: Large-area plasmonic hot-spot arrays: sub-2 nm interparticle separations with plasma-enhanced atomic layer deposition of Ag on periodic arrays of Si nanopillars.
abstract: Initial reports of plasmonic 'hot-spots' enabled the detection of single molecules via surface-enhanced Raman scattering (SERS) from random distributions of plasmonic nanoparticles. Investigations of systems with near-field plasmonically coupled nanoparticles began, however, the ability to fabricate reproducible arrays of such particles has been lacking. We report on the fabrication of large-area, periodic arrays of plasmonic 'hot-spots' using Ag atomic layer deposition to overcoat Si nanopillar templates leading to reproducible interpillar gaps down to <2 nm. These plasmonic 'hot-spots' arrays exhibited over an order of magnitude increase in the SERS response in comparison to similar arrays with larger interpillar separations.
authors.affiliation: US Naval Research Laboratory, Washington, DC 20375 USA. joshua.caldwell@nrl.navy.mil
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Caldwell
authors.forename: Orest J
authors.initials: OJ
authors.lastname: Glembocki
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Bezares
authors.forename: Maarit I
authors.initials: MI
authors.lastname: Kariniemi
authors.forename: Jaakko T
authors.initials: JT
authors.lastname: Niinistö
authors.forename: Timo T
authors.initials: TT
authors.lastname: Hatanpää
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Rendell
authors.forename: Maraizu
authors.initials: M
authors.lastname: Ukaegbu
authors.forename: Mikko K
authors.initials: MK
authors.lastname: Ritala
authors.forename: Sharka M
authors.initials: SM
authors.lastname: Prokes
authors.forename: Charles M
authors.initials: CM
authors.lastname: Hosten
authors.forename: Markku A
authors.initials: MA
authors.lastname: Leskelä
authors.forename: Richard
authors.initials: R
authors.lastname: Kasica
mesh_terms: D006046:Gold / Q000737:chemistry*; D015336:Molecular Probe Techniques; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D012825:Silicon / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D006046:Gold; D012825:Silicon