Ultrafast graphene photodetector


Graphene research so far has focused on electronic1,2,3,4,5,6 rather than photonic applications, in spite of its impressive optical properties7,8. These include its ability to absorb 2% of incident light over a broad wavelength range despite being just one atom thick7. Here, we demonstrate ultrafast transistor-based photodetectors made from single- and few-layer graphene. The photoresponse does not degrade for optical intensity modulations up to 40 GHz, and further analysis suggests that the intrinsic bandwidth may exceed 500 GHz. The generation and transport of photocarriers in graphene differ fundamentally from those in photodetectors made from conventional semiconductors as a result of the unique photonic and electronic properties of the graphene. This leads to a remarkably high bandwidth, zero source–drain bias and dark current operation, and good internal quantum efficiency.

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Figure 1: Electrical characterizations of the graphene photodetector.
Figure 2: Optical characterizations of the graphene photodetector.
Figure 3: Graphene photodetector circuit model and analysis.


  1. 1

    Novoselov, K. S. et al. Electric field effect in atomically thin carbon films. Science 306, 666–669 (2004).

    CAS  Article  Google Scholar 

  2. 2

    Novoselov, K. S. et al. Two-dimensional gas of massless Dirac fermions in graphene. Nature 438, 197–200 (2005).

    CAS  Article  Google Scholar 

  3. 3

    Zhang, Y., Tan, J. W., Stormer, H. L. & Kim, P. Experimental observation of the quantum Hall effect and Berry's phase in graphene. Nature 438, 201–204 (2005).

    CAS  Article  Google Scholar 

  4. 4

    Avouris, Ph., Chen, Z. & Perebeinos, V. Carbon-based electronics, Nature Nanotech. 2, 605–615 (2007).

    CAS  Google Scholar 

  5. 5

    Geim, A. K. & Novoselov, K. S. The rise of graphene. Nature Mater. 6, 183–191 (2007).

    CAS  Article  Google Scholar 

  6. 6

    Lin, Y. M. et al. Operation of graphene transistors at gigahertz frequencies. Nano Lett. 9, 422–426 (2009).

    CAS  Article  Google Scholar 

  7. 7

    Nair, R. R. et al. Fine structure constant defines visual transparency of graphene. Science 320, 1308 (2008).

    CAS  Article  Google Scholar 

  8. 8

    Wang, F. et al. Gate-variable optical transition in graphene. Science 320, 206–209 (2008).

    CAS  Article  Google Scholar 

  9. 9

    Chuang, S. Physics of Optoelectronic Devices (Wiley, 1995).

    Google Scholar 

  10. 10

    Li, Z. Q. et al. Dirac charge dynamics in graphene by infrared spectroscopy. Nature Phys. 4, 532–535 (2008).

    CAS  Article  Google Scholar 

  11. 11

    Ryzhii, V., Mitin, V., Ryzhii, M., Ryabova, N. & Otsuji, T. Device model for graphene nanoribbon phototransistor. Appl. Phys. Exp. 1, 063002 (2008).

    Article  Google Scholar 

  12. 12

    Vasko, F. T. & Ryzhii, V. Voltage and temperature dependencies of conductivity in gated graphene. Phys. Rev. B 76, 233404 (2007).

    Article  Google Scholar 

  13. 13

    George, P. A. et al. Ultrafast optical-pump terahertz-probe spectroscopy of the carrier relaxation and recombination dynamics in epitaxial graphene. Nano Lett. 8, 4248–4251 (2008).

    CAS  Article  Google Scholar 

  14. 14

    Rana, F. et al. Carrier recombination and generation rates for intravalley and intervalley phonon scattering in graphene. Phys. Rev. B 79, 115447 (2009).

    Article  Google Scholar 

  15. 15

    Lee, E. J. H., Balasubramanian, K., Weitz, R. T., Burghard, M. & Kern, K. Contact and edge effects in graphene devices. Nature Nanotech. 3, 486–490 (2008).

    CAS  Article  Google Scholar 

  16. 16

    Xia, F. et al. Photocurrent imaging and efficient photon detection in a graphene transistor. Nano Lett. 9, 1039–1044 (2009).

    CAS  Article  Google Scholar 

  17. 17

    Mueller, T., Xia, F., Freitag, M., Tsang, J. & Avouris, Ph. Role of contacts in graphene transistors: a scanning photocurrent study. Phys. Rev. B 79, 245430 (2009).

    Article  Google Scholar 

  18. 18

    Ishibashi, T. et al. InP/InGaAs uni-travelling-carrier photodiodes. IEICE Trans. Electron. E83-C, 938–949 (2000).

    Google Scholar 

  19. 19

    Ito. H., Furuta, T., Kodama, S. & Ishibashi, T. InP/InGaAs uni-travelling-carrier photodiodes with a 340 GHz bandwidth. Electron. Lett. 36, 1809–1810 (2000).

    CAS  Article  Google Scholar 

  20. 20

    Kato, K., Kawano, K. & Kozen, A. Design of ultra-wide band, high sensitivity p–i–n photodetectors. IEICE Trans. Electron. E76-C, 214–221 (1993).

    Google Scholar 

  21. 21

    Xia, F. et al. An asymmetric twin-waveguide high-bandwidth photodiode using a lateral taper coupler. IEEE Photon. Technol. Lett. 13, 845–847 (2001).

    Article  Google Scholar 

  22. 22

    Gmachl, C. et al. New frontiers in quantum cascade lasers and applications. IEEE J. Sel. Top. Quantum Electron. 6, 931–947 (2000).

    Article  Google Scholar 

  23. 23

    Mittleman, D. M., Jacobsen, R. H. & Nuss, M. C. T-ray imaging. IEEE J. Sel. Top. Quantum Electron. 3, 679–692 (1996).

    Article  Google Scholar 

  24. 24

    Wang, J., Gudiksen, M. S., Duan, X., Cui, Y. & Lieber, C. M. Highly polarized photoluminescence and photodetection from single indium phosphide nanowires. Science 293, 1455–1457 (2001).

    CAS  Article  Google Scholar 

  25. 25

    Ferrari, A. C. et al. Raman spectrum of graphene and graphene layers. Phys. Rev. Lett. 97, 187401 (2006).

    CAS  Article  Google Scholar 

  26. 26

    Wolff, I. Coplanar Microwave Integrated Circuits Ch.1 (Wiley, 2006).

    Google Scholar 

  27. 27

    Demiguel, S. Analysis of partially depleted absorber waveguide photodiodes. IEEE J. Lightwave Technol. 23, 2505–2512 (2005).

    CAS  Article  Google Scholar 

  28. 28

    Guo, J., Yoon, Y. & Ouyang, Y. Gate electrostatics and quantum capacitance of graphene nanoribbons. Nano Lett. 7, 1935–1940 (2007).

    CAS  Article  Google Scholar 

  29. 29

    Sze, S. M., Coleman, D. J. & Loya, A. Current transport in metal–semiconductor–metal (MSM) structures. Solid-State Electron. 14, 1209–1218 (1971).

    CAS  Article  Google Scholar 

  30. 30

    Meric, I. et al. Current saturation in zero-bandgap, top-gated graphene field-effect transistors. Nature Nanotech. 3, 654–659 (2008).

    CAS  Article  Google Scholar 

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The authors are grateful to M. Freitag and Z. Chen for helpful discussions, to Y. Vlasov, S. Assefa, W. Green, C. Schow and L. Schares for help with the radio-frequency measurements, to J. Tsang for Raman measurements, and to B. Ek and J. Bucchignano for technical assistance. F.X. is indebted to C.Y. Sung for his encouragement. T.M. acknowledges financial support by the Austrian Science Fund FWF (Erwin Schrödinger fellowship J2705-N16).

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Correspondence to Fengnian Xia or Phaedon Avouris.

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Xia, F., Mueller, T., Lin, Ym. et al. Ultrafast graphene photodetector. Nature Nanotech 4, 839–843 (2009). https://doi.org/10.1038/nnano.2009.292

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