Core-level broadening mechanisms at silicon surfaces

This article deals with the different mechanisms responsible for core-level broadening as observed by high-resolution photoelectron spectroscopy. Base d on a comparative study for three different Si(lll) surfaces the fundament al questions of symmetric or asymmetric broadening and scattered electron b ackground are discussed together with the relative contribution of Lorentzi an and Gaussian widths to the final core-level broadening. The variation of core-level broadening with temperature is studied at very low temperatures T similar to 30-300 K in order to evaluate the contribution of phonon broa dening for the silicon bulk and the surface components. (C) 1999 Elsevier S cience B.V. All rights reserved.