Facile Synthesis of Wafer-Scale Single-Crystal Graphene Film on Atomic Sawtooth Cu Substrate

Wafer-scale single-crystal (SC) graphene film is highly required for industrial applications including electronic, photonic, and optoelectronic devices. While SC graphene film has been successfully synthesized on SC Cu (111) or H-Ge (110) substrates, preparation methods of SC growth substrate are still not practical. Here, we report the facile synthesis of wafer-scale SC graphene film on atomic sawtooth Cu substrate by means of chemical vapor deposition. Atomic sawtooth Cu substrates are prepared by melting Cu foils on W foils and solidifying them. The substrates are subsequently employed for synthesis of SC graphene without formation of grain boundaries. The electron diffraction patterns, visualized by transmission electron microscopy, reveal that graphene film has the same lattice orientation over the whole region. Furthermore, Raman mapping measurement demonstrates the homogeneity of the optical property of SC graphene films. Our method provides a new route for the synthesis of SC graphene, as well as other two-dimensional materials.