The electronic structure around a point defect in an annealed TiO2(110)-(1x1) surface was studied by scanning tunnelling microscopy/spectroscopy. At a defect site of bridging O, an unoccupied defect state was found at 1.2eV above the Fermi level. Trapped electrons at the gap states were found on fivefold-coordinated Ti ion rows by current imaging tunnelling spectroscopy. The electronic states of an O defect were calculated by using the spin-polarized discrete variational (DV)-Xα method within a cluster model. The calculated defect states were in good agreement with experimental results.

Scanning Tunneling Microscopy/Spectroscopy Study of Point Defects on a TiO2 (110)-(1 x 1) Surface. Sakai, Y., Ehara, S.: Japanese Journal of Applied Physics - 2, 2001, 40[7B], L773-5