Publication

Abstract

We have developed a Sum-Frequency Generation (SFG) spectrometer allowing sensitive and highly resolved (1.8 cm-1) vibrational spectroscopy in the mid-infrared (2-10 µm) using a dedicated picosecond optical parametric oscillator. Combining SFG and infrared absorption-reflection spectroscopy, we pinpoint the occurrence of dynamical charge transfer at the C60/Ag(111) interface. The induced strong infrared activation of the C60 Ag(2) mode (~1440 cm-1) and its softening are quenched upon K-doping. This allows us to infer the coupling strength of the Ag(2) vibration to the t1u orbital of C60.

Author addresses

1. Laboratoire de Spectroscopie Moléculaire de Surface (LASMOS)
   Institute for Studies in Interface Science (ISIS)
   Facultés Universitaires Notre-Dame de la Paix (FUNDP)
   61 Rue de Bruxelles, B-5000 Namur, Belgium



2. Laboratoire pour l'Utilisation du Rayonnement Electromagnétique (LURE)
   Centre National de la Recherche Scientifique (CNRS)
   Bâtiment 209D, F-91405 Orsay, France



3. Also LASIR-CNRS, 2 rue Henry Dunant, F-94320 Thiais, France