Ultraviolet photoemission studies of thallium

Abstract

Measurements of photoemitted electron distributions from thallium polycrystalline films are reported for photon energies in the range 7.0-10.5 eV. The results are interpreted in terms of the energy distribution of the joint density of states which was calculated from the bandstructure as obtained by Ament and de Vroomen (1977). This bandstructure is found to describe the experimental spectra quite satisfactorily. Evidence is found that the calculated s derived valence bands should be lowered somewhat with respect to the Fermi level. Certain features in the experimental spectra can be assigned to emission from localised surface states.