▎ 摘　　要

The chemical states of a graphene layer after N-2 plasma treatment were investigated by using X-ray photoelectron spectroscopy and Raman spectroscopy. The graphene layer were deposited on a Cu film by using the chemical vapor deposition method. The graphene surface was exposed to a N-2 plasma in vacuum chamber at room temperature. By controlling the time of N-2 plasma treatment, we could identify the C-N bonding state in the C 1s spectra and the quaternary N state in the N 1s spectra. The valence band edge was shifted to higher binding energy by the N-2 plasma treatment. These imply that the nitrogen atom is chemisorbed in the graphene layer, replacing the carbon atom, by N-2 plasma treatment and that the Fermi level of the graphene layer is shifted up due to the electron supply from the N atom. The decrease in the intensity ratio D/G in Raman spectroscopy also supports that the N atom is chemisorbed in the graphene layer.