Advertisement

Brazilian Journal of Physics

, Volume 47, Issue 6, pp 589–593 | Cite as

Raman Excitation Profile of the G-band Enhancement in Twisted Bilayer Graphene

  • G. S. N. Eliel
  • H. B. Ribeiro
  • K. Sato
  • R. Saito
  • Chun-Chieh Lu
  • Po-Wen Chiu
  • C. Fantini
  • A. Righi
  • M. A. Pimenta
Condensed Matter

Abstract

A resonant Raman study of twisted bilayer graphene (TBG) samples with different twisting angles using many different laser lines in the visible range is presented. The samples were fabricated by CVD technique and transferred to Si/SiO2 substrates. The Raman excitation profiles of the huge enhancement of the G-band intensity for a group of different TBG flakes were obtained experimentally, and the analysis of the profiles using a theoretical expression for the Raman intensities allowed us to obtain the energies of the van Hove singularities generated by the Moiré patterns and the lifetimes of the excited state of the Raman process. Our results exhibit a good agreement between experimental and calculated energies for van Hove singularities and show that the lifetime of photoexcited carrier does not depend significantly on the twisting angle in the range intermediate angles (𝜃 between 10 and 15). We observed that the width of the resonance window (Γ ≈ 250 meV) is much larger than the REP of the Raman modes of carbon nanotubes, which are also enhanced by resonances with van Hove singularities.

Keywords

Twisted bilayer graphene Moiré pattern Resonance Raman spectroscopy 

Notes

Acknowledgements

This work was partially supported by Brazilian Institute of Science and Technology (INCT) in Carbon Nanomaterials and the Brazilian agencies Fapemig, CAPES and CNPq. The authors thank Profs. P. Venezuela and L. G. Cancado for helpful discussions. RS acknowledges MEXT grants (25107005 and 25286005).

References

  1. 1.
    K.S. Novoselov, A.K. Geim, S.V. Morozov, D. Jiang, Y. Zhang, S.V. Dubonos, I.V. Grigorieva, A.A. Firsov, Science. 306(5696), 666 (2004).  https://doi.org/10.1126/science.1102896 ADSCrossRefGoogle Scholar
  2. 2.
    J.M.B. Lopes dos Santos, N.M.R. Peres, A.H. Castro Neto, Phys. Rev. Lett. 99, 256802 (2007).  https://doi.org/10.1103/PhysRevLett.99.256802 ADSCrossRefGoogle Scholar
  3. 3.
    K. Sato, R. Saito, C. Cong, T. Yu, M.S. Dresselhaus, Phys. Rev. B. 86, 125414 (2012).  https://doi.org/10.1103/PhysRevB.86.125414 ADSCrossRefGoogle Scholar
  4. 4.
    G. Li, A. Luican, J.L. Dos Santos, A.C. Neto, A. Reina, J. Kong, E. Andrei, Nat. Phys. 6(2), 109 (2009)CrossRefGoogle Scholar
  5. 5.
    P. Moon, M. Koshino, Phys. Rev. B. 87, 205404 (2013).  https://doi.org/10.1103/PhysRevB.87.205404 ADSCrossRefGoogle Scholar
  6. 6.
    R.W. Havener, H. Zhuang, L. Brown, R.G. Hennig, J. Park, Nano Lett. 12(6), 3162 (2012)ADSCrossRefGoogle Scholar
  7. 7.
    K. Kim, S. Coh, L.Z. Tan, W. Regan, J.M. Yuk, E. Chatterjee, M.F. Crommie, M.L. Cohen, S.G. Louie, A. Zettl, Phys. Rev. Lett. 108, 246103 (2012).  https://doi.org/10.1103/PhysRevLett.108.246103 ADSCrossRefGoogle Scholar
  8. 8.
    Z. Ni, L. Liu, Y. Wang, Z. Zheng, L.J. Li, T. Yu, Z. Shen, Phys. Rev. B. 80, 125404 (2009).  https://doi.org/10.1103/PhysRevB.80.125404 ADSCrossRefGoogle Scholar
  9. 9.
    H.B. Ribeiro, K. Sato, G.S.N. Eliel, E.A.T. de Souza, C.C. Lu, P.W. Chiu, R. Saito, M.A. Pimenta, Carbon. 90, 138 (2015).  https://doi.org/10.1016/j.carbon.2015.04.005 CrossRefGoogle Scholar
  10. 10.
    Y. Wang, Z. Su, W. Wu, S. Nie, N. Xie, H. Gong, Y. Guo, J. Hwan Lee, S. Xing, X. Lu, H. Wang, X. Lu, K. McCarty, S.S. Pei, F. Robles-Hernandez, V.G. Hadjiev, J. Bao, Appl. Phys. Lett. 103(12), 123101 (2013).  https://doi.org/10.1063/1.4821434 ADSCrossRefGoogle Scholar
  11. 11.
    R. He, T.F. Chung, C. Delaney, C. Keiser, L.A. Jauregui, P.M. Shand, C.C. Chancey, Y. Wang, J. Bao, Y.P. Chen, Nano Lett. 13(8), 3594 (2013).  https://doi.org/10.1021/nl4013387. PMID: 23859121ADSCrossRefGoogle Scholar
  12. 12.
    C.C. Lu, Y.C. Lin, Z. Liu, C.H. Yeh, K. Suenaga, P.W. Chiu, ACS Nano. 7(3), 2587 (2013).  https://doi.org/10.1021/nn3059828. PMID: 23448165CrossRefGoogle Scholar
  13. 13.
    V. Carozo, C. Almeida, B. Fragneaud, P. Bedê, M. Moutinho, J. Ribeiro-Soares, N. Andrade, A. Souza Filho, M. Matos, B. Wang, et al., Phys. Rev. B. 88(8), 085401 (2013)ADSCrossRefGoogle Scholar
  14. 14.
    R.W. Havener, Y. Liang, L. Brown, L. Yang, J. Park, Nano Lett. 14(6), 3353 (2014). PMID: 24798502ADSCrossRefGoogle Scholar
  15. 15.
    C. Fantini, A. Jorio, M. Souza, M.S. Strano, M.S. Dresselhaus, M.A. Pimenta, Phys. Rev. Lett. 93, 147406 (2004).  https://doi.org/10.1103/PhysRevLett.93.147406 ADSCrossRefGoogle Scholar

Copyright information

© Sociedade Brasileira de Física 2017

Authors and Affiliations

  • G. S. N. Eliel
    • 1
  • H. B. Ribeiro
    • 2
  • K. Sato
    • 3
  • R. Saito
    • 4
  • Chun-Chieh Lu
    • 5
  • Po-Wen Chiu
    • 5
  • C. Fantini
    • 1
  • A. Righi
    • 1
  • M. A. Pimenta
    • 1
  1. 1.Departamento de FisicaUFMGBelo HorizonteBrazil
  2. 2.Departamento de Engenharia EletricaUniversidade Presbiteriana MackenzieSão PauloBrazil
  3. 3.National Institute of TechnologySendai CollegeSendaiJapan
  4. 4.Department of PhysicsTohoku UniversitySendaiJapan
  5. 5.Department of Electrical EngineeringNational Tsing Hua UniversityHsinchuTaiwan

Personalised recommendations