QUANTIZATION OF ELECTRON-STATES IN ULTRATHIN XENON LAYERS

Physisorbed Xe was grown at temperatures T less than or equal to 55 K in a layer-by-layer mode on Ag(111) and Cu(100). High-resolution norma l-emission photoelectron spectra from the Xe 5p valence levels show cl ear evidence for a quantization of the electron states, depending on t he layer thickness. Their energies and their numbers can be explained within a very simple potential well model. We have also determined val ues for the electron mean free path in solid xenon from the attenuatio n of core level photoemission intensities.