Electrical Control of Chemical Vapor Deposition of Graphene.

Chemical vapor deposition (CVD) is widely used for the efficient growth of low-dimensional materials. The growth mechanism comprises mass and heat transport, gas-phase and surface chemical reactions, and the interaction between the product and the substrate/catalyst. Correspondingly, the controllable parameter space is conventionally focused on the mass flow of each component, the temperature of the reaction chamber and the substrate, and the material and structure of the substrate/catalyst. Here, we report that applying an electric field between the copper substrate and a counter electrode has significant impacts on the growth of graphene. Electrochemical effect and ionic collision effect are observed in different conditions. With the assistance of negative and positive voltages applied on the growth substrate, selective growth and rapid growth of clean graphene films are achieved, respectively. We anticipate such electrical control will open up new ways to assist the synthesis of two-dimensional (2D) materials.