▎ 摘　　要

Atmospheric pressure chemical vapor deposition is employed to synthesize the N-doped graphene, which is mainly composed of pyrrolic type N bonding configuration with a controllable doping concentration from similar to 1.6% to similar to 6.4%. Transmission electron microscope, X-ray photoelectron spectroscopy, and Raman spectrometer are used for characterizing the pyrrolic N-doped graphene. X-ray photoelectron spectra confirm the dominant pyrrolic N bonding configuration, which is consistent with the Raman spectra compared with the pristine graphene. THz time-domain spectroscopy, four-probe DC electrical measurements, and visible spectroscopy are also utilized to analyze doping concentration qualitatively. The investigation suggests that THz wave is sensitive to the dopant concentration, which is relevant to the conductivity, while the visible light is insensitive to the dopant concentration. Our results further extend the synthesis method of N-doped graphene and the new type doped graphene might have potential applications in electrochemistry, electronics, photonics, and THz devices. (C) 2013 Elsevier Ltd. All rights reserved.