An all-atom kinetic Monte Carlo model for chemical vapor deposition growth of graphene on Cu(1 1 1) substrate

Abstract

Various graphene morphologies (compact hexagonal, dendritic, and circular domains) have been observed during chemical vapor deposition (CVD) growth on Cu substrate. The existing all-atom kinetic Monte Carlo (kMC) models, however, are unable to reproduce all these graphene morphologies, suggesting that some crucial atomistic events that dictate the morphology are missing. In this work, we propose an all-atom kMC model to simulate the graphene CVD growth on Cu substrate. Besides the usual atomistic events, such as the deposition and diffusion of carbon species on the substrate, and their attachments to the edge, we further include three other important events, that is, the edge attachment of carbon species to form a kink, the diffusion of carbon species along the edge, and the rotation of dimers to form kinks. All the energetic parameters of these events are obtained from first-principles calculations. With this new model, we successfully predict the growth of various graphene morphologies, which are consistent with the morphology phase diagram. In addition to confirming that carbon dimers are the dominant feeding species, we also find that the dominance level depends on the growth flux and temperature. Therefore, the proposed model is able to capture the growth kinetics, providing a useful tool for controlled synthesis of graphene with desired morphologies.