Thermally induced chemistry and electron-mediated processes of pyridine on (2×1) and modified Si(1 0 0) surfaces: evidence of electron-induced condensation oligomerization

The room-temperature (RT) adsorption and surface reactions of pyridine on Si(1 0 0)2 × 1 have been investigated by thermal desorption spectrometry, low-energy electron diffraction, and Auger electron spectroscopy. In addition to molecular desorption, evidence of dissociation into smaller fragments, including C2H2 and atomic hydrogen, was also found upon thermal desorption of pyridine chemisorbed on Si(1 0 0)2 × 1 at RT. Other possible surface processes such as hydrogen abstraction, fragmentation and dissociative desorption have also been identified on Si(1 0 0)2 × 1 surfaces modified by sputtering, and pre- and post-exposure of molecular oxygen and of atomic hydrogen. Evidence of condensation oligomerization of pyridine at RT has been found on Si(1 0 0)2 × 1 upon irradiated by low-energy electrons and on an oxidized Si surface even without electron mediation.