Vertical-Graphene-Assisted Chemical Vapor Deposition for Fast Growth of Macroscaled Graphene Grains

Fast growth of macroscaled single-layered graphene (MSLG) is crucial for massive fabrication of graphene with the chemical vapor deposition (CVD) method. The conventional CVD process of MSLG fabrication is time-consuming since the dosage rate of carbon precursors such as methane is usually very low in order to decrease the nucleation density of graphene grains. A few and even over 10 h are usually needed to grow graphene grains with a macroscale. Simply increasing the flow rate of the carbon precursor results in the increase of nucleation density of graphene grains, which in turn leads to a sharp decrease of the graphene grain size. Here, we report a modified CVD method which substantially accelerates the growth rate of graphene without increasing the nucleation density of graphene grains. Ceramic plates and defect-rich vertical graphene are used synergistically to assist the growth of MSLG. The ceramic plate acts as a persistent oxygen supplement which constrains the nucleation density of graphene grains, while defect-rich vertical graphene serves as complementary catalysis which can accelerate the growth speed of graphene grains. Only a few minutes are needed for the growth of millimeter-sized graphene grains with this modified CVD method.