Raman spectra of graphene ribbons

Saito, Riichiro; Furukawa, Masaru; Dresselhaus, G.; Dresselhaus, M. S.

doi:10.1088/0953-8984/22/33/334203

Cited by 57 publications

(73 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Calculation of the phonon dispersion relations is performed within a force constant model with the interatomic potential including up to the 20th nearest neighbor which is fitted from a first-principles calculation [43,44]. Figure 2(a) shows the calculated results of the phonon dispersion relations (solid lines) and the corresponding experimental phonon dispersion relations (dots) for comparison from Refs.…”

Section: A Raman Intensitymentioning

confidence: 99%

Fermi energy dependence of first- and second-order Raman spectra in graphene: Kohn anomaly and quantum interference effect

et al. 2016

View full text Add to dashboard Cite

Intensities of the first-and the second-order Raman spectra are calculated as a function of the Fermi energy. We show that the Kohn anomaly effect, i.e., phonon frequency renormalization, in the first-order Raman spectra originates from the phonon renormalization by the interband electron-hole excitation, whereas in the second-order Raman spectra, a competition between the interband and intraband electron-hole excitations takes place. By this calculation, we confirm the presence of different dispersive behaviors of the Raman peak frequency as a function of the Fermi energy for the first-and the second-order Raman spectra, as observed in some previous experiments. Moreover, the calculated results of the Raman intensity sensitively depend on the Fermi energy for both the first-and the second-order Raman spectra, indicating the presence of the quantum interference effect. The electron-phonon matrix element plays an important role in the intensity increase (decrease) of the combination (overtone) phonon modes as a function of the Fermi energy.

show abstract

Section: A Raman Intensitymentioning

confidence: 99%

Fermi energy dependence of first- and second-order Raman spectra in graphene: Kohn anomaly and quantum interference effect

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The vibrational properties and phonon band structure have been calculated with empirical potentials [29] and DFT [30,31]. In addition, there have been theoretical predictions [32,33] of the Raman spectrum, in good agreement with experiments [14,34]. For a finite AGNR the role of zigzag termini states have been studied theoretically, comparing DFT to the many-body Hubbard model [35].…”

Section: Introductionmentioning

confidence: 77%

“…It has a width of W = 4 zigzag "chains" (4-ZGNR) corresponding to a C-C edge distance of 7.26Å. The breaking of sublattice symmetry for the ZGNR and lack of pseudophase result in different selection rules for the matrix elements and difference in for example Raman signals [33]. The ZGNR generally presents spin-polarized edge states exhibiting a small band gap at the DFT level [1], in our case E g ≈ 0.6 eV (we note that this gap disappears in simpler tight-binding descriptions [1] or spin-degenerate DFT calculations).…”

Section: B Pristine Zigzag Nanoribbonmentioning

confidence: 99%

Identification of pristine and defective graphene nanoribbons by phonon signatures in the electron transport characteristics

2015

View full text Add to dashboard Cite

Inspired by recent experiments where electron transport was measured across graphene nanoribbons (GNRs) suspended between a metal surface and the tip of a scanning tunneling microscope [Koch et al., Nat. Nanotechnol. 7, 713 (2012)], we present detailed first-principles simulations of inelastic electron tunneling spectroscopy (IETS) of long pristine and defective armchair and zigzag nanoribbons under a range of charge carrier conditions. For the armchair ribbons we find two robust IETS signals around 169 and 196 mV corresponding to the D and G modes of Raman spectroscopy as well as additional fingerprints due to various types of defects in the edge passivation. For the zigzag ribbons we show that the spin state strongly influences the spectrum and thus propose IETS as an indirect proof of spin polarization.

show abstract

“…The BPM has been previously used for the computation of Raman spectra of CNTs, graphene and nano-ribbons [54,55], and provides a complementary empirical approach for estimating Raman intensities. One limitation of the model 230 is that it cannot be applied to resonant Raman spectra.…”

Section: Raman Intensitiesmentioning

confidence: 99%

“…One limitation of the model 230 is that it cannot be applied to resonant Raman spectra. The BPM has been used in conjunction with periodic calculations using a force-constant model [54,55] and DFT [18], thus avoiding the computationally expensive determination of the polarisability derivatives via quantum chemical calculations. Within the BPM, the bond polarisability for a pair of atoms is given as…”

Section: Raman Intensitiesmentioning

confidence: 99%

An empirical force field for the simulation of the vibrational spectroscopy of carbon nanomaterials

Tailor

Wheatley

Besley

2017

Carbon

View full text Add to dashboard Cite

An empirical force field for carbon based upon the Murrell-Mottram potential is developed for the calculation of the vibrational frequencies of carbon nanomaterials. The potential is reparameterised using data from density functional theory calculations through a Monte-Carlo hessian-matching approach, and when used in conjunction with the empirical bond polarisability model provides an accurate description of the non-resonant Raman spectroscopy of carbon nanotubes and graphene. With the availability of analytical first and second derivatives, the computational cost of evaluating harmonic vibrational frequencies is a fraction of the cost of corresponding quantum chemical calculations, and makes the accurate atomistic vibrational analysis of systems with thousands of atoms possible. Subsequently, the non-resonant Raman spectroscopy of carbon nanotubes and graphene, including the role of defects and carbon nanotube junctions is explored.

show abstract

Raman spectra of graphene ribbons

Cited by 57 publications

References 55 publications

Fermi energy dependence of first- and second-order Raman spectra in graphene: Kohn anomaly and quantum interference effect

Fermi energy dependence of first- and second-order Raman spectra in graphene: Kohn anomaly and quantum interference effect

Identification of pristine and defective graphene nanoribbons by phonon signatures in the electron transport characteristics

An empirical force field for the simulation of the vibrational spectroscopy of carbon nanomaterials

Contact Info

Product

Resources

About