Scanning tunneling microscopy as a probe for photophysical properties of metal nanostructures

We report the results of STM-induced photon emission experiments performed on several types of nanostructures deposited or fabricated onto atomically flat (111) gold surfaces. We demonstrate the simultaneous observation of co ntrasts both from chemically inhomogeneous and homogeneous nanostructures. In the latter case the mechanisms of the contrast involves only geometrical factors and we observe a resonance in excitation spectroscopy that we attr ibute to a localized plasmon oscillation mode. Our results illustrate the o pportunities offered by STM-induced photon emission experiments as a photop hysical probe technique with high-spatial resolution. (C) 2000 Elsevier Sci ence B.V. All rights reserved.