In order to manufacture electronic devices, graphene in the form of large-area flakes is required. Ideally, such sheets should be composed of graphene single crystals with no or negligible defects. The most commonly used method for preparing graphene involves chemical vapor deposition (CVD) of graphene on a metal surface. The CVD growth of graphene is carried out by depositing gaseous reactants on the substrate.
When the gas comes into contact with the substrate, it reacts, forming a film of material on the surface of the substrate. Generally, a copper surface is considered an excellent substrate because a single layer of graphene can be specifically formed on it. On the other hand, the nickel surface acts as a support for the controlled formation of several layers of graphene. The temperature of the substrate must be precisely controlled during the growth of graphene CVD, which determines the type of reaction that will occur. Chemical vapor deposition can be performed relatively quickly and on a large enough scale to enable large-scale production of graphene.