Uniform wafer scale synthesis of graphen

This article demonstrated monolayer graphene grown on annealed Cu (111) films on standard oxidized 100-mm Si wafers with higher quality than existing reports. Large area Raman mapping indicated high uniformity (>97% coverage) of monolayer graphene with immeasurable defects (>95% defect-negligible) across the entire wafer. Key to these results is the phase transition of evaporated copper films from amorphous to (111) preferred crystalline, which resulted in subsequent growth of high quality graphene, as corroborated by X-ray diffraction and electron backscatter diffraction. Noticeably, such phase transition of the copper film was observed on a technologically ubiquitous Si wafer with a standard amorphous thermal oxide. A modified two-step etching transfer process was introduced to preserve the clean surface and electrical property of transferred monolayer graphene. The fabricated graphene field effect transistor on a flexible polyimide film achieved peak mobility over 4900 cm2/(V s) at ambient condition.