High resolution gas phase photoabsorption spectra of SiCl 4 and Si(CH 3) 4 at the silicon l edges: characterization and assignment of resonances

Abstract

High resolution gas phase photoabsorption spectra of SiCl 4, and Si(CH 3) 4 have been measured using synchrotron radiation in the 100–225 eV photon energy range. This range encompasses the Si 2p, Si 2s and Cl 2p edges. Comparison with previous spectra shows that the high resolution is essential for characterizing all Si 2p features - both the narrow intense pre-edge features, and the broader above edge shape resonances. The Si 2s spectra, along with MS Xα calculations, enable assignment of the more complex Si 2p shape resonances. There is good agreement between theory and experiment for the Si 2p and Si 2s SiCl 4 shape resonance positions. The general shape of the shape resonance structure above the Si 2p and Si 2s edges of Si(CH 3) 4 is well reproduced by the Xα calculations.