▎ 摘　　要

Bilayer graphene has attracted significant interest because of its unique properties, including fascinating electrical behavior when one layer is slightly rotated relative to the other. However, the quality of large-area bilayer graphene is often limited by the layer-plus-island growth mode in which islands of thicker graphene present as unavoidable impurities. Here, we report the observation of the layer-by-layer, Frank-van der Merwe (FM) growth mode in bilayer graphene where multilayer impurities are suppressed. Instead of the conventional surface adhesive energy, we found it possible to tune interface adhesive energy with an oxidative pretreatment. The FM-grown bilayer graphene is of AB stacking or with small twisting angle (theta = 0 degrees similar to 5 degrees) which is more mechanically robust compared with monolayer graphene, facilitating a free-standing wet transfer technology.