PHOTON-EMISSION AT MOLECULAR RESOLUTION INDUCED BY A SCANNING TUNNELING MICROSCOPE

The tip-surface region of a scanning tunneling microscope (STM) emits light when the energy of the tunneling electrons is sufficient to exci te luminescent processes. These processes provide access to dynamic as pects of the local electronic structure that are not directly amenable to conventional STM experiments. From monolayer films of carbon-60 fu llerenes on gold(110) surfaces, intense emission is observed when the STM tip is placed above an individual molecule. The diameter of this e mission spot associated with carbon-60 is approximately 4 angstroms. T hese results demonstrate the highest spatial resolution of light emiss ion to date with a scanning probe technique.