Charge neutrality of quasi-free-standing monolayer graphene induced by the intercalated Sn layer

Kim, Hidong; Dugerjav, Otgonbayar; Lkhagvasuren, Altaibaatar; Seo, Jae M.

doi:10.1088/0022-3727/49/13/135307

Cited by 16 publications

(12 citation statements)

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“…Additionally, a shift of approximately 0.7-2.0eV in bulk SiC C 1s and Si 2p peak positions is often observed in the XPS spectrum as a result of intercalation. 9,15,18,[27][28][29][30][31][32][33][34][35] This shift indicates a change in the charge transfer between SiC and EG caused by the presence of an intercalant layer.…”

Section: Epitaxial Graphene On Silicon Carbide: Growth and Characteri...mentioning

confidence: 99%

Epitaxial graphene/silicon carbide intercalation: a minireview on graphene modulation and unique 2D materials

et al. 2019

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Intercalation of atomic species through epitaxial graphene layers began only a few years following its initial report in 2004. 1 The impact of intercalation on the electronic properties of the graphene is well known; however, the intercalant itself can also exhibit intriguing properties not found in nature. This suggests that a shift in the focus of epitaxial graphene intercalation studies may lead to fruitful exploration of many new forms of traditionally 3D materials. In the following forwardlooking review, we summarize the primary techniques used to achieve and characterize EG intercalation, and introduce a new, facile approach to readily achieve metal intercalation at the graphene/silicon carbide interface. We show that simple thermal evaporation-based methods can effectively replace complicated synthesis techniques to realize large-scale intercalation of nonrefractory metals. We also show that these methods can be extended to the formation of compound materials based on intercalation. Two-dimensional (2D) silver (2D-Ag) and large-scale 2D gallium nitride (2D-GaNx) are used to demonstrate these approaches.

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Section: Epitaxial Graphene On Silicon Carbide: Growth and Characteri...mentioning

confidence: 99%

Epitaxial graphene/silicon carbide intercalation: a minireview on graphene modulation and unique 2D materials

et al. 2019

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“…Such high electronic density of states is a characteristic of the metallic Sn-Si interface and has never been observed for other intercalants. Kim et al [34] previously claimed the metallicity of this Sn-Si interface but the inferior quality of the buffer layer sample used with significant density of states at EF before intercalation depreciates their statement. Peaks at binding energies of about 0.3, 1.2 and 2.6 eV may originate from the quantum well states due to the potential relief of the valence bands at the interface [35].…”

Section: Resultsmentioning

confidence: 93%

Metal-dielectric transition in Sn-intercalated graphene on SiC(0001)

2017

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The Sn intercalation into a buffer layer graphene grown on 4H-SiC(0001) substrate has been studied with spectroscopic photoemission and low energy electron microscope. Both SnSi x and SnOx interfacial layers are found to form below the buffer layer, converting it into a quasi-freestanding monolayer graphene. Combining the various operation modes of the microscope allows a detailed insight into the formation processes of the interlayers and their thermal stability. In particular, at the interface we observed a reversible transition from silicide to oxide after exposure to ambient pressure and subsequent annealing. This metal-dielectric transition might be useful for interface engineering in graphene-based devices.

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“…3(b) (the peak observed at ~0.4 eV below E F and at E F denoted by a black arrow is due to the absence of a well defined quasiparticle state by the energy gap at E D [25]). The formation of a disordered silicon-metal layer in the SiC substrate has been reported to significantly reduce substrate influence for the cases of epitaxial graphene with gold [13] and tin [15]. The silicon-metal layer could be responsible for the charge transfer back to the substrate, which realizes charge-neutral graphene and further lifting of the sublattice symmetry, leading to a larger energy gap than that of as-grown graphene, as observed in Fig.…”

Section: Discussionmentioning

confidence: 99%

“…On the other hand, the spontaneous polarization by charge redistribution from silicide [15,34] is assumed to be responsible for the decoupling of graphene from the substrate and the metal-to-insulator transition.…”

Section: Discussionmentioning

confidence: 99%

“…However, in practice, its gapless semi-metallic nature [5] and inevitable substrate effects, such as hybridization and charge transfer [6][7][8][9], make it difficult to utilize graphene as a building block for device applications while preserving the characteristic properties of free-standing graphene. Therefore, decoupling of graphene from the substrate, especially aligning Dirac energy, E D , with Fermi energy, E F , and opening of an energy gap at E D have been two of the key objectives in graphene research [9][10][11][12][13][14][15][16][17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

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Gapped Nearly Free-Standing Graphene on an SiC(0001) Substrate Induced by Manganese Atoms

Hwang

Lee

Kang

et al. 2018

Appl. Sci. Converg. Technol.

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The electron band structure of manganese-adsorbed graphene on an SiC(0001) substrate has been studied using angle-resolved photoemission spectroscopy. Upon introducing manganese atoms, the conduction band of graphene, that is observed in pristine graphene indicating intrinsic electrondoping by the substrate, completely disappears and the valence band maximum is observed at 0.4 eV below Fermi energy. At the same time, the slope of the valence band decreases by the presence of manganese atoms, approaching the electron band structure calculated using the local density approximation method. The former provides experimental evidence of the formation of nearly freestanding graphene on an SiC substrate, concomitant with a metal-to-insulator transition. The latter suggests that its electronic correlations are efficiently screened, suggesting that the dielectric property of the substrate is modified by manganese atoms and indicating that electronic correlations in grpahene can also be tuned by foreign atoms. These results pave the way for promising device applications using graphene that is semiconducting and charge neutral.

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Charge neutrality of quasi-free-standing monolayer graphene induced by the intercalated Sn layer

Cited by 16 publications

References 50 publications

Epitaxial graphene/silicon carbide intercalation: a minireview on graphene modulation and unique 2D materials

Epitaxial graphene/silicon carbide intercalation: a minireview on graphene modulation and unique 2D materials

Metal-dielectric transition in Sn-intercalated graphene on SiC(0001)

Gapped Nearly Free-Standing Graphene on an SiC(0001) Substrate Induced by Manganese Atoms

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