VIBRATIONALLY RESOLVED CORE-LEVEL PHOTOELECTRON-SPECTROSCOPY - SI 2P LEVELS OF SIH4 AND SIF4 MOLECULES

High-resolution photoelectron spectra (total instrumental width 0.1 eV) of the Si 2p core levels of SiH4 and SiF4 were obtained using the Aladdin undulator source. The vibrationally resolved Si 2p photoelectron spectrum of SiH4 yields a Si-H stretching energy of 0.295±0.002 eV for the core-hole ion and a lifetime width of 45 meV. Numerous vibrational lines are observed in the SiF4 Si 2p photoelectron spectrum. The Z+1 core-equivalent model is assessed and changes in the molecular geometries and bonding properties of the molecules upon ionization are discussed. © 1990 The American Physical Society.