Healing mechanism of multi-vacancy defective graphene under carbon irradiation

Abstract

The irradiation healing process of defective graphene was studied by reactive molecular dynamics simulation of injecting C atoms on a multi-vacancy graphene sheet. We studied the effect of environment temperature and incident energy of injected atoms on healing process of defective graphene. Our simulations show that a relatively high temperature (about 1600 K) is prerequisite for perfect healing of defective graphene. Moreover, an appropriate incident energy for injected atoms (0.16 eV/atom for ∼1800 K) is also necessary for perfect healing, even under a suitable temperature for perfect healing. Defect structures, such as carbon chains and blister-like structures, will occur and hinder the healing process, if the adsorption process (determined basically by incident energy) is faster than the reorganization process (dominated by temperature). In addition, the temperature dependence of reorganization capability of graphene was further studied by molecular dynamics simulation of relaxing an intact graphene sheet with adsorbed atoms. The analysis of the evolution of various micro-structures, emerged during the reorganization simulations, is helpful for deeply understanding the healing mechanism of defective graphene sheet under carbon irradiation.

Keywords:

• Defective graphene
• Healing mechanism
• Carbon irradiation
• Incident energy
• Molecular dynamics simulation

Acknowledgments

The project was supported by the National Natural Science Foundation of China (Grant No. 51775066) and the Fundamental Research Funds for the Central Universities of China (Grant No. 106112017CDJPT280002).