Oxidation as A Means to Remove Surface Contaminants on Cu Foil Prior to Graphene Growth by Chemical Vapor Deposition

One of the more common routes to fabricate graphene is by chemical vapor deposition (CVD). This is primarily because of its potential to scale up the process and produce large area graphene. For the synthesis of large area monolayer Cu is probably the most popular substrate since it has a low carbon solubility enabling homogeneous single-layer sheets of graphene to form. This process requires a very clean substrate. In this work we look at the efficiency of common pretreatments such as etching or wiping with solvents and compare them to an oxidation treatment at 1025 °C followed by a reducing process by annealing in H2. The oxidation/reduction process is shown to be far more efficient allowing large area homogeneous single layer graphene formation without the presence of additional graphene flakes which form from organic contamination on the Cu surface.