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Electrically tunable excitonic light-emitting diodes based on monolayer WSe2 p–n junctions

Nature Nanotechnology volume 9, pages 268–272 (2014)Cite this article

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Abstract

The development of light-emitting diodes with improved efficiency, spectral properties, compactness and integrability is important for lighting, display, optical interconnect, logic and sensor applications1,2,3,4,5,6,7,8. Monolayer transition-metal dichalcogenides have recently emerged as interesting candidates for optoelectronic applications due to their unique optical properties9,10,11,12,13,14,15,16. Electroluminescence has already been observed from monolayer MoS2 devices17,18. However, the electroluminescence efficiency was low and the linewidth broad due both to the poor optical quality of the MoS2 and to ineffective contacts. Here, we report electroluminescence from lateral p–n junctions in monolayer WSe2 induced electrostatically using a thin boron nitride support as a dielectric layer with multiple metal gates beneath. This structure allows effective injection of electrons and holes, and, combined with the high optical quality of WSe2, yields bright electroluminescence with 1,000 times smaller injection current and 10 times smaller linewidth than in MoS2 (refs 17,18). Furthermore, by increasing the injection bias we can tune the electroluminescence between regimes of impurity-bound, charged and neutral excitons. This system has the required ingredients for new types of optoelectronic device, such as spin- and valley-polarized light-emitting diodes, on-chip lasers and two-dimensional electro-optic modulators.

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Figure 1: Monolayer WSe2 p–n junctions.
Figure 2: Photoresponse of monolayer p–n junction at 100 K.
Figure 3: Photoluminescence and electroluminescence.
Figure 4: Tuning valley-exciton electroluminescence at 60 K.

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References

  1. Chen, J. et al. Bright infrared emission from electrically induced excitons in carbon nanotubes. Science 310, 1171–1174 (2005).

    Article  CAS  Google Scholar 

  2. Marty, L. et al. Exciton formation and annihilation during 1D impact excitation of carbon nanotubes. Phys. Rev. Lett. 96, 136803 (2006).

    Article  CAS  Google Scholar 

  3. Mann, D. et al. Electrically driven thermal light emission from individual single-walled carbon nanotubes. Nature Nanotech. 2, 33–38 (2007).

    Article  CAS  Google Scholar 

  4. Kioseoglou, G. et al. Intershell exchange and sequential electrically injected spin populations of InAs quantum-dot shell states. Phys. Rev. Lett. 101, 227203 (2008).

    Article  CAS  Google Scholar 

  5. Xia, F., Steiner, M., Lin, Y. & Avouris, P. A microcavity-controlled, current-driven, on-chip nanotube emitter at infrared wavelengths. Nature Nanotech. 3, 609–613 (2008).

    Article  CAS  Google Scholar 

  6. Essig, S. et al. Phonon-assisted electroluminescence from metallic carbon nanotubes and graphene. Nano Lett. 10, 1589–1594 (2010).

    Article  CAS  Google Scholar 

  7. Mueller, T. et al. Efficient narrow-band light emission from a single carbon nanotube p–n diode. Nature Nanotech. 5, 27–31 (2010).

    Article  CAS  Google Scholar 

  8. Shambat, G. et al. Ultrafast direct modulation of a single-mode photonic crystal nanocavity light-emitting diode. Nature Commun. 2, 539 (2011).

    Article  Google Scholar 

  9. Mak, K. F., Lee, C., Hone, J., Shan, J. & Heinz, T. F. Atomically thin MoS2: a new direct-gap semiconductor. Phys. Rev. Lett. 105, 2–5 (2010).

    Article  Google Scholar 

  10. Splendiani, A. et al. Emerging photoluminescence in monolayer MoS2 . Nano Lett. 10, 1271–1275 (2010).

    Article  CAS  Google Scholar 

  11. Cao, T. et al. Valley-selective circular dichroism of monolayer molybdenum disulphide. Nature Commun. 3, 887 (2012).

    Article  Google Scholar 

  12. Feng, J., Qian, X., Huang, C-W. & Li, J. Strain-engineered artificial atom as a broad-spectrum solar energy funnel. Nature Photon. 6, 866–872 (2012).

    Article  CAS  Google Scholar 

  13. Mak, K. F., He, K., Shan, J. & Heinz, T. F. Control of valley polarization in monolayer MoS2 by optical helicity. Nature Nanotech. 7, 494–498 (2012).

    Article  CAS  Google Scholar 

  14. Xiao, D., Liu, G-B., Feng, W., Xu, X. & Yao, W. Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides. Phys. Rev. Lett. 108, 1–5 (2012).

    Google Scholar 

  15. Zeng, H., Dai, J., Yao, W., Xiao, D. & Cui, X. Valley polarization in MoS2 monolayers by optical pumping. Nature Nanotech. 7, 490–493 (2012).

    Article  CAS  Google Scholar 

  16. Jones, A. M. et al. Optical generation of excitonic valley coherence in monolayer WSe2 . Nature Nanotech. 8, 634–638 (2013).

    Article  CAS  Google Scholar 

  17. Sundaram, R. S. et al. Electroluminescence in single layer MoS2 . Nano Lett. 13, 1416–1421 (2013).

    Article  CAS  Google Scholar 

  18. Ye, Y. et al. Exciton-related electroluminescence from monolayer MoS2 . Preprint at http://lanl.arXiv.org/abs/1305.4235 (2013).

  19. Novoselov, K. S. et al. Two-dimensional atomic crystals. Proc. Natl Acad. Sci. USA 102, 10451–10453 (2005).

    Article  CAS  Google Scholar 

  20. Mak, K. F. et al. Tightly bound trions in monolayer MoS2 . Nature Mater. 12, 207–211 (2013).

    Article  CAS  Google Scholar 

  21. Ross, J. S. et al. Electrical control of neutral and charged excitons in a monolayer semiconductor. Nature Commun. 4, 1474 (2013).

    Article  Google Scholar 

  22. Zhu, Z. Y., Cheng, Y. C. & Schwingenschlögl, U. Giant spin–orbit-induced spin splitting in two-dimensional transition-metal dichalcogenide semiconductors. Phys. Rev. B 84, 153402 (2011).

    Article  Google Scholar 

  23. Yuan, H. et al. Zeeman-type spin splitting controlled by an electric field. Nature Phys. 9, 563–569 (2013).

    Article  CAS  Google Scholar 

  24. Zhao, W. et al. Evolution of electronic structure in atomically thin sheets of WS2 and WSe2 . ACS Nano 7, 791–797 (2013).

    Article  CAS  Google Scholar 

  25. Yin, Z. et al. Single-layer MoS2 phototransistors. ACS Nano 6, 74–80 (2012).

    Article  CAS  Google Scholar 

  26. Lopez-Sanchez, O., Lembke, D., Kayci, M., Radenovic, A. & Kis, A. Ultrasensitive photodetectors based on monolayer MoS2 . Nature Nanotech. 8, 1–5 (2013).

    Article  Google Scholar 

  27. Huang, J-K. et al. Large-area synthesis of highly crystalline WSe2 monolayers and device applications. ACS Nano 8, 923–930 (2014).

    Article  CAS  Google Scholar 

  28. Korn, T., Heydrich, S., Hirmer, M., Schmutzler, J. & Schüller, C. Low-temperature photocarrier dynamics in monolayer MoS2 . Appl. Phys. Lett. 99, 102109 (2011).

    Article  Google Scholar 

  29. Shi, H. et al. Exciton dynamics in suspended monolayer and few-layer MoS2 2D crystals. ACS Nano 7, 1072–1080 (2013).

    Article  CAS  Google Scholar 

  30. Lagarde, D. et al. Carrier and polarization dynamics in monolayer MoS2 . Phy. Rev. Lett. 112, 047401 (2014).

    Article  CAS  Google Scholar 

  31. Sim, S. et al. Exciton dynamics in atomically thin MoS2: interexcitonic interaction and broadening kinetics. Phys. Rev. B 88, 075434 (2013).

    Article  Google Scholar 

  32. Yao, W., Xiao, D. & Niu, Q. Valley-dependent optoelectronics from inversion symmetry breaking. Phys. Rev. B 77, 235406 (2008).

    Article  Google Scholar 

  33. Pospischil, A., Furchi, M. M. & Mueller, T. Solar-energy conversion and light emission in an atomic monolayer p–n diode. Nature Nanotech. http://dx.doi.org/10.1038/nnano.2014.14 (2014).

  34. Baugher, B. W. H., Churchill, H. O. H., Yang, Y. & Jarillo-Herrero, P. Optoelectronic devices based on electrically tunable p–n diodes in a monolayer dichalcogenide. Nature Nanotech. http://dx.doi.org/10.1038/nnano.2014.25 (2014).

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Acknowledgements

This work was mainly supported by the US Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division (DE-SC0008145). N.G., J.Y. and D.M. are supported by the US DoE, BES, Materials Sciences and Engineering Division. W.Y. is supported by the Research Grant Council of Hong Kong (HKU705513P), the University Grant Committee (AoE/P-04/08) of the government of Hong Kong and the Croucher Foundation under the Croucher Innovation Award. D.C. is supported by the US DoE, BES, Materials Sciences and Engineering Division (DE‐SC0002197). Device fabrication was performed at the Washington Nanofabrication Facility and National Science Foundation-funded Nanotech User Facility.

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Authors and Affiliations

  1. Department of Materials Science and Engineering, University of Washington, Seattle, 98195, Washington, USA

    Jason S. Ross & Xiaodong Xu

  2. Department of Physics, Justus Liebig University, Giessen, 35392, Germany

    Philip Klement, David H. Cobden & Xiaodong Xu

  3. Department of Physics, University of Washington, Seattle, 98195, Washington, USA

    Philip Klement & Aaron M. Jones

  4. Department of Physics and Astronomy, University of Tennessee, Knoxville, 37996, Tennessee, USA

    Nirmal J. Ghimire & D. G. Mandrus

  5. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, 37831, USA, Tennessee

    Nirmal J. Ghimire, Jiaqiang Yan & D. G. Mandrus

  6. Department of Materials Science and Engineering, University of Tennessee, Knoxville, 37996, Tennessee, USA

    Jiaqiang Yan & D. G. Mandrus

  7. Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, 305-0044, Ibaraki, Japan

    Takashi Taniguchi, Kenji Watanabe & Kenji Kitamura

  8. Department of Physics and Center of Theoretical and Computational Physics, University of Hong Kong, Pokfulam Road, Hong Kong, China

    Wang Yao

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Contributions

X.X. conceived the experiments. J.S.R. fabricated the devices and performed the measurements, assisted by P.K. and A.M.J. J.S.R. and X.X. performed data analysis, with input from D.C. and W.Y. N.G., J.Y. and D.G.M. synthesized and performed bulk characterization measurements on the WSe2 crystals. T.T., K.W. and K.K. provided boron nitride crystals. X.X, D.C., J.S.R and W.Y. wrote the paper. All authors discussed the results.

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Correspondence to Xiaodong Xu.

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Ross, J., Klement, P., Jones, A. et al. Electrically tunable excitonic light-emitting diodes based on monolayer WSe2 p–n junctions. Nature Nanotech 9, 268–272 (2014). https://doi.org/10.1038/nnano.2014.26

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