Smooth epitaxial copper film on sapphire surface suitable for high quality graphene growth

Graphene, a two-dimensional material, can be grown on a metal substrate using chemical vapor deposition - this growth process is notably influenced by the crystal orientation and the roughness of the substrate surface. We prepared epitaxial Cu(111) films on sapphire substrates using thermal evaporation at various substrate temperatures and studied their crystal orientation and roughness. The well crystallized Cu(111) film with a smooth surface was obtained when the substrate was maintained at 473 K during the deposition. High quality graphene with few intrinsic defects was grown on this Cu film.