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

TL;DR

This paper presents a theoretical approach to analyze X-ray absorption spectra of graphene-metal interfaces, incorporating core-hole effects and validating results with experimental data to identify interaction fingerprints.

Contribution

The study introduces a comprehensive theoretical framework for NEXAFS spectra of graphene-metal systems, including core-hole screening effects and correlation with band structure calculations.

Findings

Spectral features correlate with graphene-metal interaction strength.

Theoretical spectra show excellent agreement with experimental data.

Spectral fingerprints can identify interface interaction types.

Abstract

The present manuscript 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 \pi* and \sigma* 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.