The carbon's solubility into copper is incredibly low and as a consequence largely surface diffusion and nucleation of carbon atoms are included. For this reason plus the growth kinetics, the graphene thickness is restricted to predominantly a monolayer. The big advantage is that the graphene could be grown on Cu https://www.quora.com/profile/Trevor-Flatcher-2/The-Key-Role-of-Silicon-Carbide-in-Electric-Vehicle-Batteries-Electric-vehicles-EVs-have-emerged-as-a-pivotal-solutio