Tuning properties of graphene by oxygen plasma treatment-induced defect engineering

Defects are inevitable throughout the entire graphene cycle, from fabrication to practical application. Therefore, illustrating how imperfections affect the properties of graphene is crucial. Herein, we study the structural changes, defect evolution, and property modulation via experimental research and theoretical calculation methods. The results show that graphene retains its pristine mechanical properties when in the sp3 defect regime, while the mechanical properties of graphene significantly decrease and the overall structure is eventually destroyed as the number of defects rapidly increases. In addition, the scattering effect of vacancy defects induced by oxygen plasma increases the probability of electron scattering, but the doping effect is conducive to the electrical transmission of graphene. The degree of undulation of the graphene surface influenced by oxygen plasma is negatively correlated with the internal conductivity of graphene. This work provides comprehensive guidance for modification of graphene and other two-dimensional materials via defect engineering.