Layer-by-Layer AB-Stacked Bilayer Graphene Growth Through an Asymmetric Oxygen Gateway

Compared with the semimetallic single layer graphene (SLG), large-sized bilayer graphene with a desired stacking order is extremely useful in the twilight of two-dimensional electronics era. However, limited strategies in the existing chemistry arsenal have been developed to grow AB-stacked bilayer graphene (AB-BLG) film in a more controllable and scalable fashion, and this stagnancy is hindering the industry-level mass production of AB-BLG-based devices. Here, we demonstrate a feasible method to synthesize large-area AB-BLG films by adopting an industry-compatible planar plasma-treated asymmetric SLG/Cu/Cu₂O substrate. The Cu₂O side serves as a catalytic oxygen gateway for continuous carbon diffusion through bulk Cu to grow the second graphene layer underneath the existing SLG template in a layer-by-layer manner. The as-grown graphene film can reach a BLG coverage of ∼95% with an AB-stacking percentage up to ∼99%.