Breit-Wigner-Fano line shapes in Raman spectra of graphene

Hasdeo, Eddwi H.; Nugraha, Ahmad R. T.; Dresselhaus, M. S.; Saito, Riichiro

doi:10.1103/physrevb.90.245140

Cited by 83 publications

(87 citation statements)

References 32 publications

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“…We calculated the asymmetry factor with temperatures ranging from 323 to 673 K for each metal with the following results: Au (0.21 ≤ │1/q│ ≤ 0.56), Cu (0.39 ≤ │1/q│ ≤ 0.65), Al (0.13 ≤ │1/q│ ≤ 0.39) and Ti (0.18 ≤ │1/q│ ≤ 0.49). The asymmetry factor│1/q│ = 0.05 in our case compares well with the reported values . The values of asymmetry factor can be compared with those of alkali‐metal intercalation compounds (GIC's) and m‐SWCNT's.…”

Section: Resultssupporting

confidence: 87%

“…by employing theoretical calculations of amplitudes of electronic Raman scattering and phonon spectra, and they concluded that the appearance of such asymmetry is due to the change in constructive‐destructive interference near the phonon resonance. Using this technique, they also reproduced the E F dependence of Raman spectra . Similarly, it is shown that the EPC enhancement is largely due to DOS and phonon modes of metal atoms rather than being the intrinsic property of graphene.…”

Section: Introductionmentioning

confidence: 80%

“…The possible Fano interaction between the continuum of electronic states and the discrete phonon state can be studied by Raman scattering . The BWF lineshapes in graphene have been explored by Hasdeo et al . by employing theoretical calculations of amplitudes of electronic Raman scattering and phonon spectra, and they concluded that the appearance of such asymmetry is due to the change in constructive‐destructive interference near the phonon resonance.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

An easy approach to reveal the metallic nature of graphene by Breit–Wigner–Fano lineshapes using Raman spectroscopy

Zafar

Tian

et al. 2017

J Raman Spectroscopy

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Electron–phonon coupling enhancement in metal‐doped single‐layer graphene has been investigated. Different metal adatoms were deposited on chemical vapor deposition (CVD) graphene and annealed at high temperature under vacuum. The interaction between these metals and graphene was studied by Raman spectroscopy. A significant variation in peak width has been observed as a function of annealing temperature. This broadening of the Raman features is understood as a consequence of the coupling of phonon with electron–phonon pairs, and its strength depends on the particular metal deposited. A typical softening and broadening of G peak in Raman spectrum is interpreted as Fano resonance, which is an interaction between a phonon and continuum. This asymmetry in G peak is further analyzed and fitted with Breit–Wigner–Fano lineshapes in terms of asymmetric factor (1/qBWF) for different metal‐doped samples as a function of annealing temperature. Hence we demonstrated an easy approach to study the transition from semi‐metallic to metallic nature of graphene. This study may extend the interest in electron–phonon coupling as it aims to manipulate the electronic and magnetic properties of graphene and other 2D systems. Copyright © 2017 John Wiley & Sons, Ltd.

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Section: Resultssupporting

confidence: 87%

Section: Introductionmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An easy approach to reveal the metallic nature of graphene by Breit–Wigner–Fano lineshapes using Raman spectroscopy

Zafar

Tian

et al. 2017

J Raman Spectroscopy

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“…Despite this apparent simplicity, the Raman spectrum yields a large amount of information on, amongst others, doping, strain, inter-layer interaction, and the underlying substrate [1][2][3][4] . To understand the influence of these quantities on the Raman spectrum of graphene, considerable effort has been made to understand the shape [5][6][7][8][9] , width [10][11][12][13] , height [14][15][16] , and position 11,[17][18][19][20][21] of the G and 2D peaks. While a clear picture for the 2D peak has been established 6,12,22,23 , a corresponding simple picture for the G peak is still missing.…”

Section: Introductionmentioning

confidence: 99%

Ab initio calculation of the G peak intensity of graphene: Laser-energy and Fermi-energy dependence and importance of quantum interference effects

Reichardt

Wirtz

2017

Phys. Rev. B

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We present the results of a diagrammatic, fully ab initio calculation of the G peak intensity of graphene. The flexibility and generality of our approach enables us to go beyond the previous analytical calculations in the low-energy regime. We study the laser and Fermi energy dependence of the G peak intensity and analyze the contributions from resonant and non-resonant electronic transitions. In particular, we explicitly demonstrate the importance of quantum interference and non-resonant states for the G peak process. Our method of analysis and computational concept is completely general and can easily be applied to study other materials as well.

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“…a, the ERS processes are shown (). In this case, we consider a contribution from the second‐order ERS processes because the second‐order process is a dominant contribution to the ERS (). It has been proved in the previous work that the first‐order ERS process is suppressed by the symmetry of graphene sublattices ().…”

Section: Electronic Raman Spectra Of Graphene In Uv Laser Excitationmentioning

confidence: 99%

Ultraviolet Raman spectroscopy of graphene and transition-metal dichalcogenides

Saito

Nugraha

Hasdeo

et al. 2015

Phys. Status Solidi B

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Here, we overview Raman spectroscopy of graphene and transition‐metal dichalcogenides as a function of laser excitation energy EL, especially in the ultraviolet (UV) region. The double resonance G′ (or 2D) band of graphene is calculated for the laser energy range up to 7 eV. The intensity of the G′ band is proportional to EL−1 for EL≤5eV. We also discuss electronic Raman spectra and the asymmetric Breit–Wigner–Fano lineshape of the G band in graphene for UV light. Finally, transition‐metal dichalcogenide materials show a strong optical absorption of the UV light at the M point at which we expect a two‐dimensional van Hove singularity of density of states. The double‐resonance Raman spectra for the UV light can be assigned to a combination or overtone phonons at the M point. Equi‐energy contour of initial (blue line) and intermediate (red line) states in a double‐resonance Raman process for (a) EL=3.49eV and (b) EL=6.00eV. In the case of EL=6.00eV, the blue and red lines are almost overlapped on each other. Gray‐shaded areas are possible phonon wave vectors for the double‐resonant Raman process that are measured from the center of the Brillouin zone.

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Breit-Wigner-Fano line shapes in Raman spectra of graphene

Cited by 83 publications

References 32 publications

An easy approach to reveal the metallic nature of graphene by Breit–Wigner–Fano lineshapes using Raman spectroscopy

An easy approach to reveal the metallic nature of graphene by Breit–Wigner–Fano lineshapes using Raman spectroscopy

Ab initio calculation of the G peak intensity of graphene: Laser-energy and Fermi-energy dependence and importance of quantum interference effects

Ultraviolet Raman spectroscopy of graphene and transition-metal dichalcogenides

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