Epitaxial CVD growth of high-quality graphene and recent development of 2D heterostructures

We demonstrate a novel epitaxial CVD method to grow high quality single-layer graphene using a thin Cu(111) film instead of conventional Cu foil. The atomically smooth Cu(111) catalyst produced the graphene with less defects and controlled orientation of the hexagonal lattice. The CVD graphene showed the carrier mobility as high as 20,000 cm²/Vs at room temperature. Using the uniform graphene sheet, densely aligned graphene nanoribbons were produced by a metal-assisted etching technique, resulting a high on/off ratio of 5,000. In addition, the epitaxial CVD method was applied to grow uniform double-layer graphene with more than 90% coverage. These GNRs and double-layer graphene are expected as promising candidates for semiconductor devices. Furthermore, heterostructures of MoS₂ and graphene were developed, and unique photo-responsive devices were observed.