Separation of C K-NEXAFS spectra for layer-by-layer analysis of carbon-based thin films: An n-alkane monolayer adsorbed on a monolayer graphene substrate grown on a Pt(1 1 1) surface

Highlights: •Depth-dependent C K-NEXAFS spectral separation method is demonstrated. •The spectra of n-alkane monolayer are separated from those of monolayer graphene. •The results are equivalent with those obtained by the subtraction. -- Abstract: Spectral separation methods for X-ray absorption fine structure spectroscopy at the near carbon K-edge are examined for an n-C36H74 monolayer adsorbed on a monolayer graphene grown on a Pt(1 1 1) surface. The spectra of n-C36H74 and the monolayer graphene are separated by fitting decay curves obtained for all photon energies by detecting photoelectrons as a function of the ejection angle. The results are discussed in comparison with separation results obtained by subtracting the independently measured graphene spectra as a background