Figure 4: Synchrotron-based XPS spectra of C1s.
From: Graphene etching on SiC grains as a path to interstellar polycyclic aromatic hydrocarbons formation
The spectra are shown before (black curve) and after (red curve) H treatment (550 L) at 1,200 K. Beneath the experimental data, we show their decomposition into separate curve components. A decrease in the C peak of about 28% in the surface-related components indicates that those C species have been etched away through H processing. The component appearing at 284.8 eV can be assigned to the graphene sp2 configuration. The components located at lower binding energies (about 284.0 eV) are attributed to bulk carbides and the components at the left-hand side of the spectra to the buffer layer (between graphene and SiC). Photon energy: 400 eV.
