Restoring a nearly free-standing character of graphene on Ru(0001) by oxygen intercalation

Realization of a free-standing graphene is always a demanding task. Here we use scanning probe microscopy and spectroscopy to study the crystallographic structure and electronic properties of the uniform nearly free-standing graphene layers obtained by intercalation of oxygen monolayer in the “strongly” bonded graphene/Ru(0001) interface. Spectroscopic data show that such graphene layer is heavily p-doped with the Dirac point located at 552 meV above the Fermi level. Experimental data are understood within density-functional theory approach and the observed effects are in good agreement with the theoretical data

The Study on the Medium-Sized Carbon Islands on Ru(0001) Surface

During chemical vapor deposition (CVD) growth of graphene on Ru(0001) surface, a specific C cluster, which has 13 C atoms arranged as three connected hexagons (so called 3-C-6), was supposed to be extremely stable. To verify this, we systemically explored the stabilities of carbon clusters C-N (N = 12, 13, 14) on the Ru(0001) surface by using first principle approach. While, it is surprising that neither 3-C-6 is the ground state of C-13 nor the C-13 cluster shows exceptional stability. So, based on the experimental STM image with C-3v symmetry and a dimmer of 1 nm, the magic cluster was proposed as C-21 or C-21-3C, which have the same core composed of six hexagons and three pentagons, as that studied before. This study is helpful to resolve the debate on the dominating clusters observed during graphene CVD growth and is helpful for understanding the growth mechanism of graphene CVD growth