▎ 摘　　要

Selective growth of either monolayer or bilayer graphene is of great importance. We developed a method to readily tune large area graphene growth from complete monolayer to complete bilayer. In an ambient pressure chemical vapor deposition process, we used the sample temperature at which to start the H-2 flow as the control parameter and realized the change from monolayer to bilayer growth of graphene on Cu foil. When the H-2 starting temperature was above 700 degrees C, continuous monolayer graphene films were obtained. When the H-2 starting temperature was below 350 degrees C, continuous bilayer films were obtained. Detailed characterization of the samples treated under various conditions revealed that heating without the H-2 flow caused Cu oxidation. The more the Cu substrate oxidized, the less graphene bilayer could form. (C) 2016 Author(s).