▎ 摘　　要

As chemical vapor deposition (CVD) graphene is polycrystalline, its electrical and mechanical properties can be improved significantly by increasing the size of the single-crystal domains of graphene. In this report, round-shape millimeter-size graphene domains were prepared on copper (Cu) foil by the atmospheric pressure chemical vapor deposition (APCVD) method using controllable reduction of methane (CH4). The influences of the flow mass of CH4 and the growth temperature of the graphene nucleation density were also studied in detail. The results demonstrated that the initial nucleation density increased with the increase of CH4 and the decrease of growth temperature. The measurements of optical microscopy and Raman spectra indicated that the graphene domains were monolayers with high crystal quality and good uniformity. (C) 2013 Elsevier B.V. All rights reserved.