PHOTOEMISSION FROM SINGLE-CRYSTAL XENON

Normal exit photoemission spectra from the (111) surface of a xenon single crystal indicate that the valence level emission is considerably broader than expected on the basis of band structure calculations. Similar observations from polycrystalline samples have lead Parrinello et al to propose an excitonic screening mechanism which would cause an apparent increase in the spin-orbit splitting at the Γ point. The details of the spectra reported here show, however, that the effect could simply be due to a dispersion of the bands stronger than that predicted theoretically. Anomalous intensity effects at h {combining short stroke overlay}ω = 21.2 eV are explained in terms of electron-electron scattering. © 1979.