The Carbon's solubility into copper is extremely small and for that reason mainly surface diffusion and nucleation of carbon atoms are involved. Because of this and also the growth kinetics, the graphene thickness is limited to predominantly a monolayer. The massive gain would be that the graphene is usually grown https://www.quora.com/profile/Trevor-Flatcher-2/Understanding-the-Chemical-Stability-of-Silicon-Carbide-Special-Ceramics-https-www-macrocosmmaterial-com-news-Underst