凯发

There are a number of technical barriers to overcome before graphene can play a major role in electronic applications. These barriers include the fabrication of graphene wafer, band-gap opening and control. In this talk, we will present our results on the synthesis of single crystalline graphene wafer and large domain-sized graphene with AB stacking order. By introducing carbon precursor locally on the Cu85Ni15 alloy with moderate carbon solubility, we succeed in creating one single nucleus on the wafer-sized substrate. Single nucleus regime was maintained during the growth period, following a new is other mal segregation mechanism. Carbon stored in the substrate accelerates the growth, yielding in a 1.5 inch monolayer single crystalline wafer in only 2.5 hours. Single crystalline graphene wafer could also be synthesized by aligned growth of graphene islands on the Ge(110) substrate. The lattice matching effect existing at the interface between the atomic steps on the Ge(110) surface and the graphene island edges guide the unidirectional alignment of graphene islands, which stiches seamlessly into a single crystalline graphene wafer. Growth of AB-stacked graphene was demonstrated by encaging Cu85Ni15 substrate with copper foils. The synergic effects of Cu85Ni15 and copper vapor evaporated  from copper foil yield a fast growth of ~ 300 m bilayer graphene in ~10 minutes. The copper vapor reduces the growth rate of the first layer of graphene while the carbon dissolved in the alloy boosts the growth of the subsequently developed second graphene layer with AB-stacking order. The success lies mainly in the largely reduced disparity of growth rates of the first and the second layer, one of the major reasons preventing the fast growth of large-domain-sized AB-stacked bilayer graphene. We will also briefly present our latest results on the synthesis of edge-controlled graphene nano-ribbon.