Formation of defects during fullerene bombardment and repair of vacancy defects in graphene

The use of high-energy ions or clusters to bombard graphene is emerging as a new method for the theoretical study of graphene properties. In this study, using molecular dynamics simulations and empirical potentials, the behaviors of graphene after bombardment by C60 under different initial velocities from 13.7 to 15.7 km/s were investigated. The simulations showed four types of defects: Stone–Wales defects, single vacancy defects, multiple vacancy defects, and out-of-plane carbon adatoms. The self-healing phenomenon of defective graphene was observed. In the low-speed region (< 14.5 km/s), the self-healing ability of graphene is enhanced at higher temperature. However, the effect of temperature is not obvious in the high-speed region, where velocity dominates. To repair vacancy defects in graphene, a physical method was proposed. The initial positions of lost atoms were traced, and then, the atoms were slowly dropped into the vacancy defects to effect repair. The simulations provide a fundamental understanding of bombardment between graphene and C60 and propose a new method for repairing vacancy defects in graphene.