Repeatable Wafer-Scale Growth of Single-Crystal Monolayer Graphene on a Hydrogen-Terminated Germanium
The uniform growth of single-crystal graphene over wafer-scale area remains a challenge in the commercial realization of various electronic, photonic, mechanical, and other devices based on graphene. We describe wafer-scale growth of wrinkle-free single crystal monolayer graphene on silicon wafer using hydrogen-terminated germanium (Ge) buffer layer. Anisotropic 2-fold symmetry on the Ge(110) surface allowed uni-directional alignment of multiple seeds, which were merged to uniform single-crystal graphene with pre-defined orientation. The weak interaction between graphene and underlying H-terminated Ge surface allowed the facile etch-free dry transfer of graphene and recycling of the Ge substrate for continual graphene growth.