ELECTRONIC-STRUCTURE OF MOS2 AND ALPHA-MOTE2 BY PHOTOELECTRON-SPECTROSCOPY USING LINE AND SYNCHROTRON SOURCES

Photoelectron spectroscopy studies have been conducted for UHV-cleaved single crystals of MoS2 and alpha -MoTe2. Angle-integrated studies have been conducted for a range of incident photon energies. For the variation of peak intensities with increasing photon energy the contributions from d-like and p-like bands have been separated. These variations can, to a first approximation, be understood in terms of the energy dependence of photoionisation cross sections from tightly bound initial states to plane wave final states. Angle-resolved photoemission studies were conducted at one value of the photon energy (21.2 eV). The observed angular variations of spectral intensities are discussed in terms of the symmetry of the initial state wave functions and possible multiple scattering effects. Two-dimensional band structures have been determined from the data, but in these materials agreement with calculated structures is not as good as for layered solids composed of lighter atoms.