▎ 摘　　要

In this paper, the morphologies of copper surface such as roughness and grain boundary were found to have crucial roles in the formation of nucleation seeds of graphene domains. We reduced the number density of graphene domains via polishing the Cu substrate in a chemical mechanical method. Scanning electron microscope and optical microscope images showed that it was preferential to form nucleation seeds along the Cu grain boundary and scratched area of the polished Cu substrate. We demonstrated that a very flat surface morphology of Cu substrate was beneficial for growing hexagonal single-crystal graphene domain which could enhance the homogeneity and electronic transport properties of graphene films. (C) 2014 Elsevier B.V. All rights reserved.