Magic Carbon Clusters in the Chemical Vapor Deposition Growth of Graphene
journal contributionposted on 15.02.2012, 00:00 authored by Qinghong Yuan, Junfeng Gao, Haibo Shu, Jijun Zhao, Xiaoshuang Chen, Feng Ding
Ground-state structures of supported C clusters, CN (N = 16, ..., 26), on four selected transition metal surfaces [Rh(111), Ru(0001), Ni(111), and Cu(111)] are systematically explored by ab initio calculations. It is found that the core–shell structured C21, which is a fraction of C60 possessing three isolated pentagons and C3v symmetry, is a very stable magic cluster on all these metal surfaces. Comparison with experimental scanning tunneling microscopy images, dI/dV curves, and cluster heights proves that C21 is the experimentally observed dominating C precursor in graphene chemical vapor deposition (CVD) growth. The exceptional stability of the C21 cluster is attributed to its high symmetry, core–shell geometry, and strong binding between edge C atoms and the metal surfaces. Besides, the high barrier of two C21 clusters’ dimerization explains its temperature-dependent behavior in graphene CVD growth.