Adsorption configurations of furan molecule on Si(100)-2×1 surface by X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectra

Abstract

The electronic and geometric structures of several possible configurations of furan(CHO) molecule chemisorbed on Si(100)-2×1 surface have been studied by X-ray spectroscopy, which is important for the design of semiconductor materials with unique properties. The Carbon K-shell (C-1s) X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra of several predicted adsorbed configurations have been simulated and calculated using density functional theory and cluster model. Our results show that the XPS and NEXAFS spectra of several possible adsorbed configurations were structurally dependent. Compared with XPS, NEXAFS spectra showed stronger structure dependence on the system; therefore, it can be well used to distinguish the configurations of furan molecule chemisorbed on Si(100)-2×1 surface. In order to explore the relationship between the spectra and structures of furan's adsorption configurations precisely, the spectral contributions of non-equivalent carbon atoms in different structural environments were also calculated.