In situ observation of step-edge in-plane growth of graphene in a STEM

摘要

It is extremely difficult to control the growth orientation of the graphene layer in comparison to Si or III-V semiconductors. Here we report a direct observation of graphene growth and domain boundary formation in a scanning transmission electron microscope, with residual hydrocarbon in the microscope chamber being used as the carbon source for in-plane graphene growth at the step-edge of bilayer graphene substrate. We show that the orientation of the growth is strongly influenced by the step-edge structure and areas grown from a reconstructed 5-7 edge are rotated by 30 degrees with respect to the mother layer. Furthermore, single heteroatoms like Si may act as catalytic active sites for the step-edge growth. The findings provide an insight into the mechanism of graphene growth and defect reconstruction that can be used to tailor carbon nanostructures with desired properties.RI Suenaga, Kazu/E-2339-2014OI Suenaga, Kazu/0000-0002-6107-1123