Natural surface oxidation consideration in first principles modeling of the X-ray absorption near edge fine structure of silicon

Abstract

First-principles calculations of the electronic structure of crystalline silicon and its dioxide were performed on the basis of the density functional theory. The full-potential linearized augmented plane waves method was used with the generalized gradient approximation for the exchange-correlation potential with Perdew, Burke and Ernzerhof functional. X-ray absorption near edge structure of silicon L3 spectra for these materials were calculated with the use of core-hole approach and supercells. These calculated spectra were used as reference for modeling the X-ray absorption L3 spectrum of a real silicon sample covered with a layer of natural SiO2 oxide. Comparison of the spectra obtained by the first principles calculations with the results of a high-resolution synchrotron experiments and the suggested approach to their modeling demonstrated the possibility of a complex silicon-oxygen system prospective materials and structures detailed study.

Keywords

• Silicon surface oxides
• Synchrotron X-ray absorption fine structure
• Ab initio calculation
• Modeling
• Electronic structure