Growth from Below: Graphene Bilayers on Ir(111)
Citations Over TimeTop 10% of 2011 papers
Abstract
We elucidate how graphene bilayers form on Ir(111). Low-energy electron diffraction (LEED) reveals that the two graphene layers are not always rotationally aligned. Monitoring this misalignment during growth shows that second-layer islands nucleate between the existing layer and the substrate. This mechanism occurs both when C segregates from the Ir and when elemental C is deposited from above. Low-energy electron microscopy (LEEM) and angle-resolved photoemission spectroscopy (ARPES) show that second-layer nucleation occurs preferentially under the first-layer rotational variants that are more weakly bound to the substrate. New-layer nucleation tends to occur inhomogeneously at substrate defects. Thus new-layer nucleation should be rapid on substrates that weakly bind graphene, making growth unstable toward mound formation initiated at substrate defects. In contrast, stronger binding permits layer-by-layer growth, as for Ru(0001). ARPES shows that bilayer graphene has two slightly p-doped π-bands. The work function of bilayer graphene is dominated by the orientation of the bottom layer.
Related Papers
- → Low energy electron microscopy and photoemission electron microscopy investigation of graphene(2012)56 cited
- → Kinetics of monolayer graphene growth by segregation on Pd(111)(2014)33 cited
- → Healing of graphene on single crystalline Ni(111) films(2014)17 cited
- → LEEM, SPLEEM and SPELEEM(2019)8 cited
- Self-organized metal-semiconductor epitaxial graphene layer on off-axis 4H-SiC（0001）(2015)