Observation of tilt boundaries in graphite by scanning tunneling microscopy and associated multiple tip effects

Albrecht, T. R.; Mizes, H. A.; Nogami, J.; Park, Sang‐il; Quate, C. F.

doi:10.1063/1.99465

Cited by 155 publications

(79 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…larger then in graphene [29,30]. The simple hexagonal lattice type can be obtained from the same relations by twisting over the special angles    .…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Spatially resolved electronic structure of twisted graphene

Yao

Bremen

Slotman³

et al. 2017

Phys. Rev. B

View full text Add to dashboard Cite

We have used scanning tunneling microscopy and spectroscopy to resolve the spatial variation of the density of states of twisted graphene layers on top of a highly oriented pyrolytic graphite substrate. Owing to the twist a moire pattern develops with a periodicity that is substantially larger than the periodicity of a single layer graphene. The twisted graphene layer has electronic properties that are distinctly different from that of a single layer graphene due to the nonzero interlayer coupling. For small twist angles (about 1-3.5 degree) the integrated differential conductivity spectrum exhibits two well-defined Van Hove singularities. Spatial maps of the differential conductivity that are recorded at energies near the Fermi level exhibit a honeycomb structure that is comprised of two inequivalent hexagonal sub-lattices. For energies |E-E_F|>0.3 eV the hexagonal structure in the differential conductivity maps vanishes. We have performed tight-binding calculations of the twisted graphene system using the propagation method, in which a third graphene layer is added to mimic the substrate. This third layer lowers the symmetry and explains the development of the two hexagonal sub-lattices in the moire pattern. Our experimental results are in excellent agreement with the tight-binding calculations.Comment: To appear in Phys. Rev.

show abstract

“…larger then in graphene [29,30]. The simple hexagonal lattice type can be obtained from the same relations by twisting over the special angles    .…”

Section: Resultsmentioning

confidence: 99%

“…The simple hexagonal lattice type can be obtained from the same relations by twisting over the special angles    . As an example we show in Figure 1 nm is the lattice constant of graphene [29,30]). …”

Section: Resultsmentioning

confidence: 99%

Spatially resolved electronic structure of twisted graphene

Yao

Bremen

Slotman³

et al. 2017

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…Most of the early STM work interpreted moiré patterns as resulting from tip effects [13,14] or misorientation of substrate layers [14][15][16][17][18]. It was Kobayashi [5,6] who first explained that moiré patterns could arise from modulation of the electronic states in an overlayer due to the interaction with a substrate.…”

Section: B Moiré Patternsmentioning

confidence: 99%

Origin of the moiré pattern in thin Bi films deposited on HOPG

et al. 2015

View full text Add to dashboard Cite

Thin Bi(110) films deposited on highly oriented pyrolytic graphite (HOPG) exhibit a pronounced moiré pattern; here the origin of the moiré pattern is investigated using scanning tunneling microscopy (STM) and spectroscopy (STS), high-resolution transmission electron microscopy (HR-TEM), and density functional theory (DFT). It is shown that the moiré pattern forms only on islands which are misoriented by ∼30• with respect to the usual substrate symmetry direction. Two models of the moiré pattern are presented: (i) a commensurate monolayer construction (CMC) for rectangular overlayer symmetry on hexagonal substrates and (ii) a qualitative model based on simple superposition of a Bi overlayer on graphene. The CMC model has previously been applied only to systems with pure hexagonal symmetry. Both models generate moiré patterns with key parameters (period, angles of the pattern measured with respect to the main HOPG and Bi crystal directions) that are consistent with the experimental results, but development of a fully predictive/quantitative model remains an outstanding challenge. The electronic structure of the moiré pattern is investigated using STS and DFT, and it is found that the local density of states (LDOS) is modulated by the moiré pattern. These results are consistent with a picture in which a small distortion of Bi atomic positions at the film-substrate interface results in periodic modulation of the LDOS, hence allowing observation of the moiré pattern in STM images.

show abstract

“…This is consistent with the structure of topological defects in polycrystalline monolayer graphene discussed below. Later, the interest in GB defects in graphene was renewed with the advent of scanning tunnelling microscopy (STM) for investigating surfaces [27][28][29][30] . Scanning tunnelling spectroscopy (STS) allowed the local electronic properties of these defects in graphite to be investigated in detail 31 .…”

Section: Structure Of Polycrystalline Graphenementioning

confidence: 99%

Polycrystalline graphene and other two-dimensional materials

2014

View full text Add to dashboard Cite

Graphene, a single atomic layer of graphitic carbon, has attracted intense attention due to its extraordinary properties that make it a suitable material for a wide range of technological applications. Large-area graphene films, which are necessary for industrial applications, are typically polycrystalline, that is, composed of single-crystalline grains of varying orientation joined by grain boundaries. Here, we present a review of the large body of research reported in the past few years on polycrystalline graphene. We discuss its growth and formation, the microscopic structure of grain boundaries and their relations to other types of topological defects such as dislocations. The review further covers electronic transport, optical and mechanical properties pertaining to the characterizations of grain boundaries, and applications of polycrystalline graphene. We also discuss research, still in its infancy, performed on other 2D materials such as transition metal dichalcogenides, and offer perspectives for future directions of research.Comment: review article; part of focus issue "Graphene applications

show abstract

Observation of tilt boundaries in graphite by scanning tunneling microscopy and associated multiple tip effects

Cited by 155 publications

References 14 publications

Spatially resolved electronic structure of twisted graphene

Spatially resolved electronic structure of twisted graphene

Origin of the moiré pattern in thin Bi films deposited on HOPG

Polycrystalline graphene and other two-dimensional materials

Contact Info

Product

Resources

About