Abstract Adsorption and thermal decomposition of H 2 S on Si(1 0 0)-2 Â 1 are studied by means of temperature-programmed desorption (TPD) and X-ray photoemission spectroscopy (XPS) with synchrotron radiation. The H 2 S molecule dissociates to form H and HS on the Si surface at adsorption temperature of 115 K. The Si(1 0 0)-2 Â 1 surface structure is conserved upon the adsorption of H 2 S due to bonding of dissociative H and HS on two Si atoms in a dimer without breaking the Si-Si dimer bond. H 2 and SiS are the only desorption products of thermal decomposition of H 2 S with peaks at 780 and 820 K, respectively. On the basis of TPD and XPS results, intermediates involved in decomposition of H 2 S and their adsorption configurations are proposed and discussed
