Scalable Growth of Single-Crystal Graphene on Hydrogen-Terminated Germanium

The uniform growth of single-crystal graphene over wafer-scale area remains a challenge in the commercial-level manufacturability of various electronic, photonic, mechanical, and other devices based on graphene. Here, I present scalable growth of wrinkle-free single-crystal monolayer graphene on a hydrogen-terminated germanium substrate. The anisotropic twofold symmetry of the Ge(110) surface allowed unidirectional alignment of multiple seeds, which were merged to uniform single-crystal graphene with pre-defined orientation. Furthermore, the weak interaction between graphene and underlying H-terminated Ge surface enabled the facile etch-free dry transfer of graphene and the recycling of the Ge substrate for continual graphene growth.