The production of large bilayer hexagonal graphene domains by a two-step growth process of segregation and surface-catalytic chemical vapor deposition

A novel two-step process combining surface catalyzed process with segregation growth was used to prepare single crystal hexagonal bilayer graphene domains on Cu metal substrates by ambient pressure chemical vapor deposition. Carbon atoms are first dissolved into the quasi-melting Cu metal at 1080 °C and then segregated on the Cu surface to form nucleation centers of single-layer graphene during cooling. The graphene crystallites spontaneously act as templates to induce the carbon atoms to form hexagonal bilayer graphene domains. The bilayer graphene domains are size-tunable by controlling the growth conditions. The yield of the bilayer graphene is over 90% and the defect-free domains reach ∼100 μm in size, greater than the reported single-layer domains.