The Fabrication of Wrinkle‐Free Graphene Patterns on Ge(110) Substrate

A thermal expansion mismatch is inevitable for graphene grown on various substrates by chemical vapor deposition, which leads to the formation of wrinkles during post‐growth cooling. Wrinkles can degrade the superior properties of graphene and increase device‐to‐device inconsistency. To address this issue, wrinkle‐free graphene patterns are grown on Ge(110) substrate with the assistance of 5 × 1016 cm−2 Si ion implantation. The experimental data show that the wrinkle‐free graphene can grow on unimplanted areas, whereas no graphene is synthesized on Si ion implanted areas. Further research shows that the wrinkle‐free nature of graphene is closely related to the compressive strain distribution in graphene. The compressive strain in graphene is increased to a significant extent with an increase in the size of graphene patterns. When the compressive strain energy exceeds the wrinkle‐formation barrier, wrinkles emerge on the graphene, and the compressive strain decreases as a consequence. This research may help to understand the formation mechanisms of graphene wrinkles and promote the growth of wrinkle‐free graphene. Wrinkle‐free graphene patterns are grown on Ge(110) substrate with the assistance of 5 × 1016 cm−2 Si ion implantation. The wrinkle‐free graphene only grows on unimplanted areas, whereas no graphene is synthesized on Si ion implanted areas. The formation of wrinkle‐free graphene is closely related to the compressive strain distribution in graphene.