Spatially-Resolved Structure and Electronic Properties of Graphene on Polycrystalline Ni

Abstract

We have used in situ low-energy electron microscopy (LEEM) to correlate the atomic and electronic structure of graphene films on polycrystalline Ni with nm-scale spatial resolution. Spatially resolved electron scattering measurements show that graphene monolayers formed by carbon segregation do not support the π-plasmon of graphene, indicating strong covalent bonding to the Ni. Graphene bilayers have the Bernal stacking characteristic of graphite and show the expected plasmon loss at 6.5 eV. The experimental results, in agreement with first-principles calculations, show that the π-band structure of free-standing graphene appears only in films with a thickness of at least two layers and demonstrate the sensitivity of the plasmon loss to the electronic structure.

Sequential synthesis of free-standing high quality bilayer graphene from recycled nickel foil

“…The spacing between graphene and Ni surface is thus reduced and was calculated as low as 2.11 Å [29]. It was reported that the p-band structure of graphene could not be found in the first two layers [30]. In that case, interaction between protruded grains and the foil is expected to be highly reduced.…”

Many‐body effects in optical response of graphene‐based structures

“…[46] Interestingly, that the p plasmon completely disappeared in a graphene-Ni interface, as it was detected experimentally and confirmed by calculations of the EEL spectra. [47] Relaxation of the top layer of a Ni slab along with graphene layers resulted in strong bonding between the components that completely disrupted the graphene p bands. Thus, plasmons can be a sensitive probe of changes in the graphene band structure.…”

Tunable Electronic and Dielectric Properties of Molybdenum Disulfide

“…Electron energy loss spectroscopy has been considered as a powerful technique over transmission electron microscopy (TEM), coupled with flake edge analysis and electron diffraction to identify the number of layers in a commercially produced large and uniform 2D sheets [67]. Furthermore, the EELS can also give information about the single electron interband transitions which can be identified in the lower energy side from the collective plasma oscillations [49].…”