Direct observation of site-specific valence electronic structure at the Si O2 Si interface

Atom specific valence electronic structures at the solid-solid interface are elucidated successfully using soft x-ray absorption and emission spectroscopy. In order to demonstrate the versatility of this method, we investigated the Si O2 Si interface as a prototype and directly observed valence electronic states projected at the particular atoms of the Si O2 Si interface; the local electronic structure strongly depends on the chemical states of each atom. In addition, we compared the experimental results with first-principles calculations, which quantitatively revealed the interface properties in atomic scale.