The microscopic structure of disproportionating amorphous silicon monoxide is studied by inelastic x-ray scattering at the silicon $L_{\text{II},\text{III}}$ edge. This material arranges into nanocrystalline regions of Si embedded in amorphous ${\text{SiO}}_2$ at proper annealing temperatures and in this work we demonstrate how the contribution of the suboxide interfaces between these regions can be extracted from the experimental data. The resulting near-edge spectra are analyzed in detail using a computational framework that combines molecular-dynamics simulations and density-functional theory calculations. The results indicate that the amount of silicon atoms with oxidation states between $+1$ and $+3$ is significant and depends strongly on the annealing temperature. Furthermore, the presented $s$, $p$, and $d$-type local densities of states $\left(\ell \text{DOS}\right)$ demonstrate that the most significant differences are found in the $p$-type $\ell \text{DOS}$.

• Received 16 February 2010

DOI:https://doi.org/10.1103/PhysRevB.81.205317