Easy Approach to Graphene Growth on Ir(111) and Ru(0001) from Liquid Ethanol

The growth of a high-quality complete graphene layer is successfully achieved for Ir(111) and Ru(0001) substrates using liquid ethanol as a precursor. Metallic substrates, which are cleaned in ultra-high vacuum conditions, were ex-situ immersed in liquid ethanol followed by the controlled in situ thermal annealing. The process of graphene formation and its quality are carefully monitored using X-ray photoelectron spectroscopy, low-energy electron diffraction, and scanning tunneling microscopy methods. It is found that graphene formation starts at 400 & DEG;C via ethanol decomposition and desorption of oxygen from the surface leading to the formation of the high-quality complete graphene layer at 1000 & DEG;C. The results of the systematic angular-resolved photoelectron spectroscopy experiments confirm the high quality of the obtained graphene layer, and it concludes that such an approach offers an easy, quick, and reproducible method to synthesize large-scale graphene on different metallic substrates.