Changes to the occupied and unoccupied electronic structure of TiO2(100) upon alkali metal reduction

Direct and inverse ultraviolet photoemission spectroscopy (UPS and IPS) are used to measure the occupied and unoccupied electronic structure of TiO 2 (100) 1 × 1 and TiO 2 (100)c(2 × 2)K. UPS results from stoichiometric TiO 2 (100) 1 × 1 are in good agreement with earlier studies. IPS data recorded from TiO 2 (100) 1 × 1 show two distinct features with energy positions 1.7 eV and 5.3 eV above the Fermi level (E F ). These features are associated with the Ti 3d derived t 2g and e g levels