High resolution core-level spectroscopy study of low-coverage lithium adsorption on the Si(100)2 × 1 surface

Abstract

In this high-resolution core-level photoelectron spectroscopy study, the adsorption of lithium on the Si(100)2 × 1 surface has been studied for low Li coverages. The basic dimer reconstruction of the clean surface was preserved up to a coverage corresponding to a work function change of Δφ=−1.8eV, as indicated by low-energy electron diffraction (LEED) and the Li 1s and Si 2p core-level spectra. The changes in the Si 2p spectra indicate that the surface reconstruction has changed from asymmetric to symmetric dimers at this 2 × 1 saturation coverage, with the dimer atoms giving rise to a single Si 2p core-level binding-energy shift of −0.37 eV. For higher Li coverages the Li atoms react with the substrate under the formation of Li silicides.