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

Abstract

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 C 2H 2 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.