The Wrinkle Formation In Graphene On Transition Metal Substrate: A Molecular Dynamics Study

To explore the mechanism of the wrinkle formation in graphene on transition metal substrate, a molecular dynamics (MD) simulation package that allows us to simulate systems of millions of atoms was developed. Via the MD simulation, we reveal the detailed kinetics of wrinkles formation on a Cu substrate under compressive strain, from nucleation to one-dimensional propagation and then the splitting of a large wrinkle to a few smaller ones, which is in good conformity with experimental observation. Further study reveals that both friction and the adhesion between graphene and Cu substrate are critical for the wrinkle formation and wrinkles can be easily formed with a lower frictional force and/or a smaller adhesion. Finally, we have shown that impurities in graphene or substrates can greatly facilitate the nucleation of wrinkles. The systematic exploration of the wrinkle formation in graphene on a substrate is expected to facilitate the experimental designs for the controllable synthesis of high-quality graphene.