Highly ordered, millimeter-scale, continuous,single-crystalline graphene monolayer formed on Ru (0001)

Highly ordered single-layer graphene was fabricated on a large scale by thermal annealing of a ruthenium single crystal Ru(0001) containing carbon. The graphene layers were grown on a Ru(0001) surface by thermal annealing and Ru crystals with surface was polished to a roughness of less than 0.03 μm, were commercially obtained. The results show that the graphene overlayer has a hexagonal instead of honeycomb lattice due to diatomic resolution of images. XPS and AES analysis of graphene layer show an increase in the intensity at 273 eV that is attributed due to carbon formation on the Ru(0001) surface. It is also found that the dimensions, long-range order, and crystallinity of the graphene layer formed depend strongly on the kinetic parameters. An inappropriately annealed Ru at wrong temperature or time leads to an Ru with 2D hexagonal lattice that is less ordered and contain high density of defects and dislocations.