Angle-resolved photoemission study of the valence-band structure of VN/sub 0.89/(100)

The electronic structure of a VN/sub 0.89/(100) single crystal has been studied using angle-resolved photoemission spectroscopy and synchrotron radiation. Recorded normal-emission spectra are compared with theoretical photoemission spectra calculated for stoichiometric composition. A good overall agreement between recorded and calculated spectra is found for photon energies below about 35 eV. A mapping of the band structure is made and compared with a theoretical bulk-band structure. The experimentally determined dispersions of the energy bands are found to be smaller than those theoretically predicted and the location of the bands deviates, in some cases considerably. A vacancy-induced structure is identified at 2.8 eV below the Fermi energy in spectra recorded at photon energies above 31 eV. The character of the vacancy-induced states and of states located close to the Fermi energy is discussed based on observed intensity enhancements above the V 3p absorption threshold