相关论文: Effects of Layer Stacking on the Combination Raman…
We report multiphonon Raman scattering in graphene samples. Higher order combination modes involving 3 phonons and 4 phonons are observed in single-layer (SLG), bi-layer (BLG), and few layer (FLG) graphene samples prepared by mechanical…
Though graphene has been intensively studied by Raman spectroscopy, in this letter, we report a study of second-order overtone and combinational Raman modes in an unexplored range of 1690-2150 cm-1 in nonsuspended commensurate (AB-stacked),…
We uncover the interlayer shear mode of multi-layer graphene samples, ranging from bilayer-graphene (BLG) to bulk graphite, and show that the corresponding Raman peak measures the interlayer coupling. This peak scales from~43cm-1 in bulk…
We show the evolution of Raman spectra with number of graphene layers on different substrates, SiO$_{2}$/Si and conducting indium tin oxide (ITO) plate. The G mode peak position and the intensity ratio of G and 2D bands depend on the…
The in-plane shear modes between neighbor-layers of 2-4 layer graphenes (LGs) and the corresponding graphene scrolls rolled up by 2-4LGs were investigated by Raman scattering. In contrast to that just one shear mode was observed in 3-4LGs,…
We report the observation of layer breathing mode (LBM) vibrations in few-layer graphene (FLG) samples of thickness from 2 to 6 layers, exhibiting both Bernal (AB) and rhombohedral (ABC) stacking order. The LBM vibrations are identified…
Two new Raman modes below 100 cm^-1 are observed in twisted bilayer graphene grown by chemical vapor deposition. The two modes are observed in a small range of twisting angle at which the intensity of the G Raman peak is strongly enhanced,…
Layer-layer coupling plays a critical role in defining the physical properties of few-layer graphene (FLG). With respect to vibrations, the interlayer coupling is predicted to create a set of N-1 finite frequency, out-of-plane interlayer…
We present a comparative measurement of the G-peak oscillations of phonon frequency, Raman intensity and linewidth in the Magneto-Raman scattering of optical E2g phonons in mechanically exfoliated ABA- and ABC-stacked trilayer graphene…
Twisted bilayer graphene (tBLG) devices with ion gel gate dielectrics are studied using Raman spectroscopy in the twist angle regime where a resonantly enhanced G band can be observed. We observe prominent splitting and intensity quenching…
An experimental study of Raman scattering in N-layer graphene as a function of the top layer doping is reported. At high doping level, achieved by a CHF_3 plasma treatment, we observe a splitting of the $G$ band in the spectra of bilayer…
The role of twist angle ($\theta_t$) in tailoring the physical properties of heterostructures is emerging as a new paradigm in two-dimensional materials. The influence of flat electronic bands near the magic angle ($\sim$1.1$^{\circ}$) on…
Naturally or artificially stacking extra layers on single layer graphene (SLG) forms few-layer graphene (FLG), which has attracted tremendous attention owing to its exceptional properties inherited from SLG and new features generated by…
We investigated Raman spectra of single-layer and multi-layer graphene under ultraviolet laser excitation at the wavelength of 325 nm. It was found that while the G peak of graphene remains pronounced in UV Raman spectra, the 2D band…
We report the growth of thickness-controlled rotationally faulted multilayer graphene (rf-MLG) on Ni foils by low-pressure chemical vapor deposition and their characterization by micro-Raman spectroscopy. The surface morphology and…
The symmetry group analysis is applied to classify the phonon modes of $N$-stacked graphene layers (NSGL's) with AB- and AA-stacking, particularly their infra-red and Raman properties. The dispersions of various phonon modes are calculated…
The electronic excitations of bilayer graphene (BLG) under a magnetic field are investigated with the use of the Peierls tight-binding model in conjunction with random-phase approximation (RPA). The interlayer atomic interactions,…
The phonon dispersions of monolayer and few-layer graphene (AB bilayer, ABA and ABC trilayers) are investigated using the density-functional perturbation theory (DFPT). Compared with the monolayer, the optical phonon $E_{2g}$ mode at…
Electron-phonon coupling (EPC) in bilayer graphene (BLG) at different doping levels is studied by first-principles calculations. The phonons considered are long-wavelength high-energy symmetric (S) and antisymmetric (AS) optical modes. Both…
The combination of field tunable bandgap, topological edge states, and valleys in the band structure, makes insulating bilayer graphene a unique localized system, where the scaling laws of dimensionless conductance g remain largely…