Quantum Confinement in Aligned Zigzag “Pseudo‐Ribbons” Embedded in Graphene on Ni(100)

Abstract

Lateral quantum confinement is of great interest in tuning the electronic properties of graphene‐based nanostructures, making them suitable for technological applications. In principle, these properties might be controlled through the edge topology: for example, zigzag nanoribbons are predicted to have spin‐polarized edge states. The practical realization of these structures is of utmost importance in fully harnessing the electronic properties of graphene. Here, the formation of regular, 1.4 nm wide ribbon‐like graphene structures with zigzag edges are reported, showing 1D electronic states. It is found that these “pseudo‐ribbons” embedded in single‐layer graphene supported on Ni(100) can spontaneously form upon carbon segregation underneath 1D graphene moiré domains, extending hundreds of nanometers in length. On the basis of both microscopy/spectroscopy/diffraction experiments and theoretical simulations, it is shown that these structures, even though seamlessly incorporated in a matrix of strongly interacting graphene, exhibit electronic properties closely resembling those of zigzag nanoribbons.

1d Selective Confinement and Diffusion of Metal Atoms on Graphene

“…1c. The Dirac cone in G disappears, due to the hybridization with the Ni-3𝑑 states, as already shown by Sala et al [43] both by the calculated electronic bands (Fig. S5 of the Supporting Information of Ref.…”

“…[21]), and thus on the basis of this argument the adsorption of adatoms should be always favored on valleys rather than on ridges. In our case, instead, the behavior is dominated by the G/substrate interaction (present both in valleys and ridges and both in stretched and in compressed G regions [43]) and thus different elements prefer different adsorption regions, as will be extensively discussed in the subsection ''Electrostatically-driven selective adsorption of adatoms on valleys and ridges''.…”

“…2 of Ref. [43]), which in valleys and ridges are clearly different with respect to the regions where G is almost free-standing (''pseudo-ribbon''). Although the hybridization destroys the peculiar features of the G electronic structure around the Fermi energy, the relative positions of the most pronounced pDOS peaks show that C 𝑉 /C 𝑅 electronic states are shifted by roughly 1 eV, as indicated by the arrows in Fig.…”

“…1c. The shift comes from the 𝑛-doping of G on Ni(100) [43], as the majority of electrons transferred from the Ni substrate to G are distributed among the C 𝑉 atoms. This charge picture is supported by the plot of the induced charge density which shows no charge transfer between the C 𝑅 atoms and the Ni substrate (Fig.…”

Towards the FAIRification of Scanning Tunneling Microscopy Images

“…In particular, Gr_Ni100 includes images taken on monolayer graphene grown by chemical vapour deposition on Ni (100). Due to the square symmetry of the substrate, the resulting layer is composed of patches of aligned graphene (aligned with the substrate crystallographic structure and showing a typical wavy 1D moirè pattern) and rotated graphene (identifiable in the images by a 2D moirè pattern) [10,11,12,13,14]. The Gr_Ni111 category contains STM images taken on monolayer graphene grown by chemical vapour deposition on Ni (111) single crystals.…”