N. Pauly, S. Tougaard, F. Yubero
Surface and Interface Analysis, 38 (2006) 872-875
doi: 10.1002/sia.2173

The surface excitation parameter (SEP) is determined by analysis of X-ray photoelectron spectroscopy (XPS) model developed by Simonsen, Yubero and Tougaard (Phys. Rev. B. 1997; 56: 1612). The model includes excitation due to the static core hole as well as the effect of the surface. The only input in the model is the dielectric function of the medium. More precisely, the SEP is extracted from the theoretical spectrum by calculating the ratio between the surface loss part of the spectrum and the elastic peak intensity. The angular distributions of the SEP are calculated for aluminium and silicon for photoelectrons of 1 and 3.4 keV energy. The SEP for XPS is found to be slightly (5–10%) smaller compared to that for reflection-electron-energy-loss spectroscopy (REELS) calculated within the same model, and this difference is ascribed to the effect of the static core hole.