Ionization energies of valence levels in physisorbed rare-gas multilayers

Abstract
Experimental data by diverse authors show that the ionization energies of valence levels of xenon atoms residing on pure metal surfaces or on top of a thin insulator slab are nearly constant. It is suggested that this independence of the ionization energy of the slab thickness is due to identical final states, brought about by a transfer of the valence-band hole during the photoionization process into the layer of the insulator closest to the metal.