| AVS 66th International Symposium & Exhibition | |
| 2D Materials | Tuesday Sessions |
| Session 2D-TuP |
| Session: | 2D Poster Session |
| Presenter: | Li Gao, California State University Northridge |
| Authors: | J. Neilson, California State University, Northridge H. Chinkezian, California State University, Northridge H. Phirke, California State University, Northridge A. Osei-Twumasi, California State University, Northridge Y. Li, Peking University, China C. Chichiri, California State University, Northridge J. Cho, Myongji University, Korea K. Palotás, Hungarian Academy of Sciences, Hungary L. Gan, Peking University, China S.J. Garrett, California State University, Northridge K.C. Lau, California State University, Northridge L. Gao, California State University Northridge |
| Correspondent: | Click to Email |
The nitrogen-containing sole precursor azafullerene has been used for the synthesis of nitrogen-doped graphene on the Cu(111) surface. The synthesis process, doping properties, and doping-induced variation of local work function of graphene have been studied on the atomic scale by combing scanning tunneling microscopy/spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations. Most nitrogen dopants are at the edges of graphene islands and the graphene domain boundaries with the pyridinic configuration. Graphitic nitrogen dopants arrange into curved lines within graphene islands after multiple growth cycles, which results from a doping process guided by the edges of graphene islands. The doping-induced variation of local work function of the graphene surface has been measured on the atomic scale by recording spatially resolved field emission resonances. We find that the local work function strongly depends on the atomic bonding configuration and concentration of nitrogen dopants. The local work function decreases for graphitic nitrogen doping but increases for pyridinic nitrogen doping. This work provides new atomic-scale insights into the process for incorporating nitrogen atoms into the graphene lattice as well as the correlations between the type of nitrogen doping and the variation of local work function.