The kinetics of crack propagation in CVD graphene film

The preparation of graphene by chemical vapor deposition (CVD) is often accompanied by the growth of some structural defects, one of which is crack. The understanding of crack formation is key to the preparation of high-quality graphene films. In this work, the crack defects of graphene grown on liquid copper substrates by chemical vapor deposition (CVD) were examined. Then, the effects of growth temperature, growth time and total pressure on kinetics of cracks were analyzed, respectively. It is found that (I) The crack appeared during the period of graphene growth, not the cooling process of graphene; (II) the crack preferred to propagate at the vertex angle of etched hexagonal holes; (III) the crack tended to orient along the same direction—the zigzag direction. Finally, a dynamic mechanism of crack growth was proposed. Our study provides significant insights into the tearing mechanism of defective graphene. • The cracks at the vertex of the etched hexagonal holes formed during the growth of graphene. • The graphene cracks preferred to propagate along the zigzag direction and they are parallel to each other. • A possible kinetics mechanism for crack propagation was proposed.