Modulation of N-bonding configurations and their influence on the electrical properties of nitrogen-doped graphene

Nitrogen-doped graphene (NG) films have been grown on Cu foils by using imidazole (C3H4N2) and PMMA as solid N and C sources. The results show that the pyridinic and pyrrolic nitrogen-bonding configurations and the N doping concentration can be effectively modulated by the hydrogen flux. In addition, it reveals that the defect density of the NG film is dominated by the pyridinic-N configuration instead of the pyrrolic-N configuration from the Raman spectra. Furthermore, from the electrical measurements, it is concluded that the pyrrolic-N configuration has stronger donor ability, and lower carrier scattering than those of pyridinic-N configuration. This study provides fundamental insights to understand the role of various N-bonding configurations, but also give guidance to synthesize the NG with controllable N-bonding configurations.