Journal of Sensor Science and Technology (센서학회지)

The Korean Sensors Society (한국센서학회)
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Effects of Optically-modulated Metal-graphene Contact on the Photoresponsivity of Graphene Photodetectors

빛에 의해 변조되는 금속-그래핀 컨택이 그래핀 포토디텍터의 광응답도에 미치는 영향

  • Lee, Chang-Ju (School of Electronics Engineering, Kyungpook National Unversity) ;
  • Shim, Jae Hoon (School of Electronics Engineering, Kyungpook National Unversity) ;
  • Park, Hongsik (School of Electronics Engineering, Kyungpook National Unversity)
  • Received : 2019.03.21
  • Accepted : 2019.03.27
  • Published : 2019.03.31
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Abstract

Graphene is recognized as a promising material for silicon photonics, since it has a wide optical-window that entirely covers the optical communication wavelength region ($1.3{\sim}1.6-{\mu}m$) and extremely high-carrier mobility that makes it possible to fabricate the high-speed photodetectors. However, the maximum absorbance of monolayer graphene is only 2.3%, which limits the photoresponse characteristics of graphene photodetectors. As a result, a low photoresponsivity of graphene photodetector is a critical issue limiting the use of graphene photodetectors in the optical communications field. In this paper, we investigated effects of optically-modulated metal-graphene contact on the photoresponsivity of graphene photodetectors. The optical modulation of the contact resistance mainly determined the photoresponse characteristics of graphene photodetectors. The Ni-contact graphene photodetector which has a characteristic of the significant optical modulation of metal-graphene contact showed a higher photoresponsivity than the Pd-contact device. This work will provide a way to improve the photoresponse characteristics of graphene-based photodetector and contribute to the development of high-speed/high-responsivity graphene photodetector.

Keywords

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Fig. 1. Schematics of (a) Pd- and Ni-contact graphene photodetector and (b) transmission-line model (TLM) pattern fabricated with a graphene layer transferred on SiO2/Si substrate. The channel length of the graphene photodetectors varies from 4 to 100 μm.

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Fig. 2. Transfer ID–VG characteristics of (a) Pd-contact and (b) Nicontact graphene photodetectors under varying drain bias from 0.2 to 1.0 V and ΔID/ID,darkversus VG characteristics of (c) Pd-contact and (d) Ni-contact graphene photodetectors under drain bias of 1.0 V.

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Fig. 3. Photoresponsivity values of Pd- and Ni-contact graphene photodetectors under varying drain bias from 0.2 to 1.0 V.

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Fig. 4. Sheet resistance versus VG characteristics of (a) Pd-contact and (b) Ni-contact graphene photodetectors under dark and irradiation conditions and contact resistivity versus VG characteristics of (c) Pd-contact and (b) Ni-contact graphene photodetectors under dark and irradiation conditions. Drain bias varies from 0.2 to 1.0 V.

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Fig. 5. (a) Compositions of contact resistances in device resistances versus channel length of the Pd- and Ni-contact graphene photodetectors and (b) compositions of optically-modulated contact resistances in optically-modulated device resistances versus channel length of the Pd- and Ni-contact graphene photodetectors.

References

  1. K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, I. V. Grigorieva, and A. A. Firsov, "Electric field effect in atomically thin carbon films", Science, Vol. 306, pp. 666-669, 2004. https://doi.org/10.1126/science.1102896
  2. A. K. Geim and K. S. Novoselov, "The rise of graphene", Nat. Mater., Vol. 6, pp. 183-191, 2007. https://doi.org/10.1038/nmat1849
  3. K. S. Novoselov, V. I. Fal'ko, L. Colombo, P. R. Gellert, M. G. Schwab, and K. Kim, "A roadmap for graphene", Nature, Vol. 490, pp. 192-200, 2012. https://doi.org/10.1038/nature11458
  4. Y. -M. Lin, C. Dimitrakopoulos, K. A. Jenkins, D. B. Farmer, H. -Y. Chiu, A. Grill, and Ph. Avouris, "100-GHz transistors from wafer-scale epitaxial graphene", Science, Vol. 327, pp. 662, 2010. https://doi.org/10.1126/science.1184289
  5. R. M. Westervelt, "Graphene nanoelectronics", Science, Vol. 320, pp. 324-325, 2008. https://doi.org/10.1126/science.1156936
  6. M. Liu, X. Yin, E. Ulin-Avila, B. Geng, T. Zentgraf, L. Ju, F. Wang, and X. Zhang, "A graphene-based broadband optical modulator", Nature, Vol. 474, pp. 64-67, 2011. https://doi.org/10.1038/nature10067
  7. X. Li, Y. Zhu, W. Cai, M. Borysiak, B. Han, D. Chen, R. D. Piner, L. Colombo, and R. S. Ruoff, "Transport of largearea graphene films for high-performance transparent conductive electrodes", Nano Lett., Vol. 9, No. 12, pp. 4359-4363, 2009. https://doi.org/10.1021/nl902623y
  8. F. Bonaccorso, Z. Sun, T. Hasan, and A. C. Ferrari, "Graphene photonics and optoelectronics", Nat. Photonics, Vol. 4, pp. 611-622, 2010. https://doi.org/10.1038/nphoton.2010.186
  9. F. Xia, T. Mueller, Y. -M. Lin, A. Valdes-Garia, and P. Avouris, "Ultrafast graphene photodetector", Nat. Nanotechnol., Vol. 4, pp. 839-843, 2009. https://doi.org/10.1038/nnano.2009.292
  10. T. Mueller, F. Xia, and Ph. Avouris, "Graphene photodetectors for high-speed optical communications", Nat. Photonics, Vol. 4, pp. 297-301, 2010. https://doi.org/10.1038/nphoton.2010.40
  11. A. Pospischil, M. Humer, M. M. Furchi, D. Bachmann, R. Guider, T. Fromherz, and T. Mueller, "CMOS-compatible graphene photodetector covering all optical communication bands", Nat. Photonics, Vol. 7, pp. 892-896, 2013. https://doi.org/10.1038/nphoton.2013.240
  12. X. Wang, Z. Cheng, K. Xu, H. K. Tsang, and J.-B. Xu, "High-responsivity graphene/silicon-heterostructure waveguide photodetectors", Nat. Photonics, Vol. 7, pp. 888-891, 2013. https://doi.org/10.1038/nphoton.2013.241
  13. M. Furchi, A. Urich, A. Pospischil, G. Lilley, K. Unterrainer, H. Detz, P. Klang, A. M. Andrews, W. Schrenk, G. Strasser, and T. Mueller, "Microcavity-Integrated Graphene Photodetector", Nano Lett., Vol. 12, pp. 2773-2777, 2012. https://doi.org/10.1021/nl204512x
  14. C.-H. Liu, Y.-C. Chang, T. B. Norris, and Z. Zhong, "Graphene photodetectors with ultra-broadband and high responsivity at room temperature", Nat. Nanotechnol., Vol. 9, pp. 273-278, 2014. https://doi.org/10.1038/nnano.2014.31
  15. G. Konstantatos, M. Badioli, L. Gaudreau, J. Osmond, M. Bernechea, F. P. G. de Arquer, F. Gatti, and F. H. L. Koppens, "Hybrid graphene-quantum dot phototransistors with ultrahigh gain", Nat. Nanotechnol., Vol. 6, pp. 1-6, 2012.
  16. H. Park, R. Beresford, R. Ha, H.-J. Choi, H. Shin, and J. Xu, "Evaluation of metal-nanowire electrical contacts by measuring contact end resistance", Nanotechnology, Vol. 23, No. 24, pp. 245201, 2012. https://doi.org/10.1088/0957-4484/23/24/245201