Application of density functional theory and photoelectron spectra to the adsorption and reaction of H₂S on Si (100)

The adsorption and reaction of H₂S on a Si(100) surface were investigated using density functional theory (DFT) and X-ray photoelectron spectra (XPS). The decomposition of H₂S results in the formation of S adatoms via a HS species. We propose four reaction paths for the decomposition of adsorbed H₂S; the corresponding structural conformations of H ₂S, HS, and S species are presented. The density of states and electron density difference were utilized to illustrate the interaction between S-containing species and surface Si atoms. The interaction of the surface Si atom and the H atom of H₂S facilitates the decomposition of adsorbed H₂S. The assignments of XPS data are correlated with the proposed intermediates during the thermal decomposition of H₂S.