Strong suppression of graphene growth by sulfur superstructure on a nickel substrate

Abstract

The formation of multilayer graphene on a nickel substrate is usually unavoidable due to the precipitation of carbon upon cooling after the growth of the single layer of graphene. We found that the growth rate of graphene on a Ni(110) surface was markedly reduced when the surface was covered by sulfur atoms arranged in a c(2×2) periodicity. An atomistic survey by scanning tunneling microscopy revealed a compression of the sulfur superstructure as a result of the growth of graphene-covered regions. Photoelectron emission microscopy showed that the growth rate of graphene is linear with time, which indicates that carbon atoms are supplied only at the growth front of graphene islands. Density functional theory calculations rationalized these experimental results and suggested a mechanism for suppressing the growth of graphene. Sulfur atoms might extend the utility of nickel substrates for the production of single-layer graphene or nanographenes.