▎ 摘　　要

This work demonstrates an integrated approach for studying graphene films with various doping levels of nitrogen. The graphene films grown by a chemical vapor deposition technique were doped by treatment in ammonia radio-frequency plasma discharge. The graphene samples were investigated by x-ray photoelectron spectroscopy with a parallel registration of photoemission angular dependence. The depth-dependent changes in the valence band structure and the nitrogen peak position were recorded. The shift of valence band maximum relative to the initial value (0.13 +/- 0.04 eV) was observed using ultraviolet photoelectron spectroscopy. The dispersion and the shift of p-plasmon maximum were registered while the percentage of nitrogen atoms in two-dimensional graphene network increased. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)