Electronic structure of nitrogen-carbon alloys(a−CNx)determined by photoelectron spectroscopy

Abstract

The electronic structure of nitrogen-containing diamondlike films prepared by sputtering was determined by photoelectron spectroscopy. The $\mathrm{N}1s$ core-level spectra are constituted by two peaks at 400.5 and 398.2 eV associated with substitutional $\mathrm{N}{\mathrm{sp}}^2$ in aromatic rings and N bonded to $\mathrm{C}{\mathrm{sp}}^3,$ respectively. On increasing N, the top of the valence band suffers profound changes. The new features are identified by a comparison of the experimental spectra with theoretically calculated density of states of nitrogen-containing graphite and ${\mathrm{C}}_3{\mathrm{N}}_4$ structures.