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Article
Thermally induced atomic reconstruction into fully commensurate structures of transition metal dichalcogenide layers
Twist angle between two-dimensional layers is a critical parameter that determines their interfacial properties, such as moiré excitons and interfacial ferro-electricity. To achieve better control over these p...
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Article
Open AccessFabrication of p-type 2D single-crystalline transistor arrays with Fermi-level-tuned van der Waals semimetal electrodes
High-performance p-type two-dimensional (2D) transistors are fundamental for 2D nanoelectronics. However, the lack of a reliable method for creating high-quality, large-scale p-type 2D semiconductors and a suitab...
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Article
Anomalous optical excitations from arrays of whirlpooled lattice distortions in moiré superlattices
Moiré superlattices formed by stacking two-dimensional crystals have reinvigorated the pursuit for emergent functionalities of engineered superlattices. Unique optical characteristics can be realized from the ...
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Article
Open AccessOptical phonons of SnSe(1−x)Sx layered semiconductor alloys
The evolution of the optical phonons in layered semiconductor alloys SnSe(1–x)Sx is studied as a function of the composition by using polarized Raman spectroscopy with six different excitation wavelengths (784.8,...
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Article
Coherent many-body exciton in van der Waals antiferromagnet NiPS3
An exciton is the bosonic quasiparticle of electron–hole pairs bound by the Coulomb interaction1. Bose–Einstein condensation of this exciton state has long been the subject of speculation in various model systems
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Article
Wafer-scale production of patterned transition metal ditelluride layers for two-dimensional metal–semiconductor contacts at the Schottky–Mott limit
A key challenge in the development of two-dimensional (2D) devices is the fabrication of metal–semiconductor junctions with minimal contact resistance and depinned energy levels. An ideal solution for practica...
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Article
Open AccessSuppression of magnetic ordering in XXZ-type antiferromagnetic monolayer NiPS3
How a certain ground state of complex physical systems emerges, especially in two-dimensional materials, is a fundamental question in condensed-matter physics. A particularly interesting case is systems belong...
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Chapter
Resonant Raman Spectroscopy of Two Dimensional Materials Beyond Graphene
The resonance Raman effects in two dimensional materials including transition metal dichalcogenides and black phosphorus are reviewed. The Raman intensities of high-frequency intra-layer vibration modes are en...
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Article
Open AccessLow-Frequency Raman Spectroscopy of Few-Layer 2H-SnS2
We investigated interlayer phonon modes of mechanically exfoliated few-layer 2H-SnS2 samples by using room temperature low-frequency micro-Raman spectroscopy. Raman measurements were performed using laser wavelen...
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Article
Open AccessStrain-shear coupling in bilayer MoS2
Layered materials such as graphite and transition metal dichalcogenides have extremely anisotropic mechanical properties owing to orders of magnitude difference between in-plane and out-of-plane interatomic in...
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Article
Open AccessExcitation energy dependent Raman spectrum of MoSe2
Raman investigation of MoSe2 was carried out with eight different excitation energies. Seven peaks, including E1g, A1g, E2g1 and A2u2 peaks are observed in the range of 100–400 cm−1. The phonon modes are assigned...
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Article
Bright visible light emission from graphene
Electrically biased suspended graphene devices show an intense electroluminescence in the visible range with a tunable emission spectrum.
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Article
Open AccessElectrical control of nanoscale functionalization in graphene by the scanning probe technique
Functionalized graphene is a versatile material that has well-known physical and chemical properties depending on functional groups and their coverage. However, selective control of functional groups on the na...
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Article
Open AccessExcitation Energy Dependent Raman Signatures of ABA- and ABC-stacked Few-layer Graphene
The dependence of the Raman spectrum on the excitation energy has been investigated for ABA-and ABC- stacked few-layer graphene in order to establish the fingerprint of the stacking order and the number of lay...
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Article
Polarization dependence of the photocurrent due to an anisotropic electron-photon interaction in Pd-graphene-Pd devices
We measured the polarization dependence of the photocurrent in symmetric Pd-graphene-Pd photodevices. The photocurrent is maximum when the polarization angle of the incident light is parallel to the edge of an...
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Article
Open AccessBetween Scylla and Charybdis: Hydrophobic Graphene-Guided Water Diffusion on Hydrophilic Substrates
The structure of water confined in nanometer-sized cavities is important because, at this scale, a large fraction of hydrogen bonds can be perturbed by interaction with the confining walls. Unusual fluidity pr...
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Article
Enhancement of the Raman scattering intensity in folded bilayer graphene
We found Raman scattering enhancement of the Raman G band in folded bilayer graphene. Its Raman intensity is more than 40 times greater than that of AB stacked Bernal bilayer graphene. The enhancement is interpre...
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Chapter
Raman Spectroscopy for Characterization of Graphene
Raman spectroscopy is one of the most widely used characterization tool in the study of graphene, a two-dimensional hexagonal crystal of carbon atoms. Owing to the resonant nature of the light scattering proce...
