Chemical vapor deposition growth of 5Â mm hexagonal single-crystal graphene from ethanol

We show that graphene single crystals as large as 5 mm can be synthesized from ethanol via chemical vapor deposition (CVD). Key conditions for the successful reduction in nucleation density are extremely low partial pressure of ethanol vapor and pre-oxidation of Cu substrates. The resulting graphene flakes are predominantly homogeneous single-layer hexagons, as characterized by Raman spectroscopy and selected area electron diffraction. However, the edge of ethanol produced graphene shows an armchair feature, suggesting a possible different mechanism from conventional methane CVD.