▎ 摘　　要

It has been shown that the hydrogen annealing process plays an important role on the crystallographic orientation changes of polycrystalline copper substrates during low pressure chemical vapor deposition (LPCVD) of graphene, which subsequently influence the generation of graphene films. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to study the copper foil crystallographic orientation and morphology changes with and without hydrogen annealing. Graphene films were successfully synthesized on copper foils by LPCVD at 1000 degrees C with hydrogen annealing process. Raman spectroscopy was also performed to determine the formation of graphene films as well as their quality. Without hydrogen annealing no significant graphene Raman signal are detected and it is hypothesized that this is related to the different crystallographic orientations of copper substrates. (C) 2015 Elsevier B.V. All rights reserved.