Theoretical description of X-ray absorption spectroscopy of the graphene-metal interfaces.

The present paper considers the application of the method of the near-edge X-ray absorption spectroscopy (NEXAFS) for the investigation of the graphene-based systems (from free-standing graphene to the metal-intercalation-like systems). The NEXAFS spectra for the selected systems are calculated in the framework of the approach, which includes the effects of the dynamic core-hole screening. The presented spectral changes from system to system are analysed with the help of the corresponding band-structure calculations. The obtained results are compared with available experimental data demonstrating the excellent agreement between theory and experiment. The direct correlation between the strength of the graphene interaction with the metallic substrate and the spectral distributions (shape and intensities of π* and σ* features in the C K NEXAFS spectra) is found that can be taken as a fingerprint for the description of interaction at the graphene/metal interface.