Ultrafast epitaxial growth of metre-sized single-crystal graphene on industrial Cu foil

A foundation of the modern technology that uses single-crystal silicon has been the growth of high- quality single-crystal Si ingots with diameters up to 12 inches or larger. For many applications of graphene, large-area high-quality （ideally of single-crystal） material will be enabling. Since the first growth on copper foil a decade ago, inch-sized single-crystal graphene has been achieved. We present here the growth, in 20 min, of a graphene film of （5 × 50） cm^2 dimension with 〉99% ultra-highly oriented grains. This growth was achieved by： （1） synthesis of metre-sized single-crystal Cu（111） foil as substrate; （2） epitaxial growth of graphene islands on the Cu（1 1 1） surface; （3） seamless merging of such graphene islands into a graphene film with high single crystallinity and （4） the ultrafast growth of graphene film. These achievements were realized by a temperature-gradient-driven annealing technique to produce single-crystal Cu（1 1 1） from industrial polycrystalline Cu foil and the marvellous effects of a continuous oxygen supply from an adjacent oxide. The as-synthesized graphene film, with very few misoriented grains （if any）, has a mobility up to ～23,000 cm^2 V^-1 s^-1 at 4 K and room temperature sheet resistance of ～230 Ω/□. It is very likely that this approach can be scaled up to achieve exceptionally large and high-quality graphene films with single crystallinity, and thus realize various industrial-level applications at a low cost.