Abstract: The electronic structure of the interface between cyclooctatetrene(COTH) and Ru metal is studied by the ultraviolet photoelectron spectroscopy(UPS). Three peaks are observed at 5.6, 7.9 and 10.2 eV below the Fermi level, they are related to the πCC, σCC and σCH bands of the phenyl in the COTH material respectively. The peak at 3.8 eV below the Fermi level is related to the C－C band with π characteristic orbit derived from the COTH containing eight phenyls. The highest occupied state (HOS) of COTH is at 1.8 eV below the Fermi level. The work function of COTH is only 3.2 eV, 1.0 eV lower than that of clean Ru. The results of the angle resolved ultraviolet photoelectron spectroscopy (ARUPS) suggest that the molecule of COTH is approximately parallel to the substrate surface.

Key words: Organic luminous material, Ultraviolet photoelectron spectroscopy, 　Electronic structure of the interface, Cyclooctatetrene(COT-H)