a SiO 2 substrate layer and a Ni interlayer, and on copper and nickel foil. The obtained
graphene layers were characterized by Raman spectroscopy. The films grown on SiO 2/Ni
substrate and Ni foil comprise mainly multilayer defect-rich graphene, while those on Cu foil
exhibit the spectroscopic fingerprint of relatively defect-free single-layer graphene due to the
low carbon solubility in copper and the suitably chosen substrate position in a quasiclosed …