▎ 摘　　要

Bilayer graphene (BLG) has aroused enormous research interest because of its unique tunable physical properties, which are dependent on the twisted angles and interlayer interaction. Therefore, controlling electronic properties of BLG is very crucial to developing its potential applications in many fields. In this article, BLG single crystals with two representative twisted angles, similar to 0 degrees and similar to 30 degrees grown by chemical vapor deposition (CVD) were specially studied. The surface potentials of pristine BLG single crystals show that the surface potential difference between single layer graphene (SLG) and BLG of similar to 0 degrees BLG is lower than similar to 30 degrees BLG. Furthermore, using diazonium salts reaction and nitrogen doping, the electrical coupling and properties of BLG are tuned reversibly. The resulting surface potential of BLG can be tuned in a wide range from 0 to 50 mV.