Measurements of the escape probability of photoelectrons and the inelasticmean free path in silver sulphide

The escape probabilities of S 2s and S 2p photoelectrons leaving an Ag2S su rface in a direction parallel to the photon flux and the inelastic mean fre e path values in the range 200-1600 eV have been determined experimentally. The escape probability as a function of depth of origin For the S 2s photo electrons exhibits non-monotonic behaviour, with a maximum at a depth of 0. 6-0.8 nm, In contrast, the escape probability of the S 2p photoelectrons le aving the surface in the same direction can be approximated hy an exponenti al function. The inelastic mean free path values determined by elastic peak electron spectroscopy agree well with the values resulting from the G1 pre dictive formula of Gries, Copyright (C) 2000 John Wiley & Sons, Ltd.