Oxidation of the polycrystalline copper-graphene nanocomposite

Abstract

Since the experimental discovery of graphene, research has progressed at an astonishing speed. This 2D honeycomb has already exhibited revolutionary electronic properties and claimed the record for strength. However, getting graphene out of the lab requires improved characterization, especially of imperfections. Hence, this paper explores one of the most important defects in a copper-graphene nanocomposite fabricated by chemical vapor deposition (CVD), which is the method most capable of producing large sheets of high-quality graphene. Through electron microscopies, optical microscopy, and Raman spectroscopy, this work details (1) the room-temperature oxidation of the copper substrate coated with graphene and (2) the heterogeneities of the graphene due to deposition and oxidation. The results indicate that this oxidation can be confined by grain boundaries, forms in the copper substrate as Cu2O, and minimally affects the graphene quality. This investigation also suggests that CVD can produce a variable number of high-quality, graphene layers.