Ultrafast Epitaxial Growth of Metre-Sized Single-Crystal Graphene

Graphene single crystal has become a promising material for next generation electronics and optoelectronics. In this talk I will introduce why we need to grow graphene faster and how fast we can achieve in our recently developed new technology. We present here the growth, in 20 min, of a graphene film of (5 × 50) cm² 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(111) 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(111) from industrial polycrystalline Cu foil and the marvelous 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 cm² V^-1 s^-1 at 4 K and room temperature sheet resistance of 230 Ω/square. It is likely that this approach can be scaled up to achieve exceptionally large and high-quality graphene with single crystallinity, and thus realize various industrial-level applications at low cost.