title: Nanoscale probing of adsorbed species by tip-enhanced Raman spectroscopy.
abstract: Tip-enhanced Raman spectroscopy (TERS) is based on the optical excitation of localized surface plasmons in the tip-substrate cavity, which provides a large but local field enhancement near the tip apex. We report on TERS with smooth single crystalline surfaces as substrates. The adsorbates were CN- ions at Au(111) and malachite green isothiocyanate (MGITC) molecules at Au(111) and Pt(110) using either Au or Ir tips. The data analysis yields Raman enhancements of about 4 x 10(5) for CN- and up to 10(6) for MGITC at Au(111) with a Au tip, probing an area of less than 100 nm radius.
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany. pettinger@fhi-berlin.mpg.de
authors.forename: Bruno
authors.initials: B
authors.lastname: Pettinger
authors.forename: Bin
authors.initials: B
authors.lastname: Ren
authors.forename: Gennaro
authors.initials: G
authors.lastname: Picardi
authors.forename: Rolf
authors.initials: R
authors.lastname: Schuster
authors.forename: Gerhard
authors.initials: G
authors.lastname: Ertl