title: Silver nanocrystal-modified silicon nanowires as substrates for surface-enhanced Raman and hyper-Raman scattering.
abstract: Metal catalyzed, CVD-grown silicon nanowires decorated by chemical assembly of closely spaced Ag nanocrystals were modified with the well-known "silver mirror" reaction and investigated as substrates for surface-enhanced Raman (SERS) and hyper-Raman (SEHRS) spectroscopy. Four chromophores were examined: Rhodamine 6G, crystal violet, a cyanine dye, and a cationic donor-acceptor substituted stilbene. After soaking the substrates overnight in 10(-4) M aqueous chromophore solutions, all four chromophores gave good-quality SERS spectra in < or =60 s using <1 microW of 458-nm cw laser power, and SEHRS spectra are obtained in < or =120 s using <1 mW of mode-locked 916-nm laser power. Results from this substrate are compared with those on colloidal silver nanoparticles deposited as a film, as well as surfaces grown by the silver mirror reaction.
authors.affiliation: School of Natural Sciences, University of California, Merced, P.O. Box 2039, Merced, CA 95340, USA.
authors.forename: Weinan
authors.initials: W
authors.lastname: Leng
authors.forename: Amir A
authors.initials: AA
authors.lastname: Yasseri
authors.forename: Shashank
authors.initials: S
authors.lastname: Sharma
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Li
authors.forename: Han Young
authors.initials: HY
authors.lastname: Woo
authors.forename: Doojin
authors.initials: D
authors.lastname: Vak
authors.forename: Guillermo C
authors.initials: GC
authors.lastname: Bazan
authors.forename: Anne Myers
authors.initials: AM
authors.lastname: Kelley
mesh_terms: D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure*; D012825:Silicon / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D012834:Silver; D012825:Silicon