Prediction of XPS spectra of silicon self-interstitials with the all-electron mixed-basis method

Abstract

Silicon self-interstitials have been investigated by local-density approximation-based ab initio all-electron calculations using a mixed-basis of atomic orbitals and planewaves for the wave functions. The results of the numerical calculations show that the bond-center, hexagonal, tetrahedral and split-〈110〉 interstitials have deeper characteristic 2p Kohn–Sham levels than those of perfect host silicon, but the split-〈001〉 interstitial does not. Hence, we predict that, within the frozen-orbital approximation, i.e., excluding the effect of electronic relaxation due to the ejected electron, the X-ray photoelectron spectroscopy spectra for the bond-center, hexagonal, tetrahedral and split-〈110〉 interstitials will have binding energies 0.4–1.1eV higher than perfect host silicon.