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Monolayer excitonic laser


Two-dimensional van der Waals materials have opened a new paradigm for fundamental physics exploration and device applications because of their emerging physical properties. Unlike gapless graphene, monolayer transition-metal dichalcogenides (TMDCs) are two-dimensional semiconductors that undergo an indirect-to-direct bandgap transition1,2,3,4,5, creating new optical functionalities for next-generation ultra-compact photonics and optoelectronics. Although the enhancement of spontaneous emission has been reported on TMDC monolayers integrated with photonic crystals6,7 and distributed Bragg reflector microcavities8,9, coherent light emission from a TMDC monolayer has not been demonstrated. Here, we report the realization of a two-dimensional excitonic laser by embedding monolayer WS2 in a microdisk resonator. Using a whispering gallery mode with a high quality factor and optical confinement, we observe bright excitonic lasing at visible wavelengths. This demonstration of a two-dimensional excitonic laser marks a major step towards two-dimensional on-chip optoelectronics for high-performance optical communication and computing applications.

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Figure 1: Design of the monolayer exitonic laser.
Figure 2: Whispering gallery modes of the monolayer excitonic laser.
Figure 3: Observation of monolayer WS2 excitonic lasing.
Figure 4: Characterizations of two-dimensional excitonic lasing.


  1. 1

    Mak, K. F., Lee, C., Hone, J., Shan, J. & Heinz, T. F. Atomically thin MoS2: a new direct-gap semiconductor. Phys. Rev. Lett. 105, 136805 (2010).

    ADS  Article  Google Scholar 

  2. 2

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

    ADS  Article  Google Scholar 

  3. 3

    Ross, J. S. et al. Electrically tunable excitonic light-emitting diodes based on monolayer WSe2 p–n junctions. Nature Nanotech. 9, 268–272 (2014).

    ADS  Article  Google Scholar 

  4. 4

    Pospischil, A., Furchi, M. M. & Mueller, T. Solar-energy conversion and light emission in an atomic monolayer p–n diode. Nature Nanotech. 9, 257–261 (2014).

    ADS  Article  Google Scholar 

  5. 5

    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. 9, 262–267 (2014).

    ADS  Article  Google Scholar 

  6. 6

    Wu, S. et al. Control of two-dimensional excitonic light emission via photonic crystal. 2D Mater. 1, 011001 (2014).

    Article  Google Scholar 

  7. 7

    Gan, X. et al. Controlling the spontaneous emission rate of monolayer MoS2 in a photonic crystal nanocavity. Appl. Phys. Lett. 103, 18119 (2013).

    Google Scholar 

  8. 8

    Liu, X. et al. Strong light–matter coupling in two-dimensional atomic crystals. Nature Photon. 9, 30–34 (2015).

    ADS  Article  Google Scholar 

  9. 9

    Schwarz, S. et al. Two-dimensional metal–chalcogenide films in tunable optical microcavities. Nano Lett. 14, 7003–7008 (2014).

    ADS  Article  Google Scholar 

  10. 10

    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).

    ADS  Article  Google Scholar 

  11. 11

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

    ADS  Article  Google Scholar 

  12. 12

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

    ADS  Article  Google Scholar 

  13. 13

    Xiao, D., Liu, G., Feng, W., Xu, X. & Yao, W. Coupled spin and valley physics in monolayer of MoS2 and other group-VI dichalcogenides. Phys. Rev. Lett. 108, 196802 (2012).

    ADS  Article  Google Scholar 

  14. 14

    Radisavijevic, B., Radenovic, A., Brivio, J., Giacometti, V. & Kis, A. Single-layer MoS2 transistors. Nature Nanotech. 6, 147–150 (2011).

    ADS  Article  Google Scholar 

  15. 15

    Mak, K. F., McGill, K. L., Park, J. & McEuen, P. L. The valley Hall effect in MoS2 transistors. Science 344, 1489–1492 (2014).

    ADS  Article  Google Scholar 

  16. 16

    Chernikov, A. et al. Exciton binding energy and nonhydrogenic Rydberg series in monolayer WS2 . Phys. Rev. Lett. 113, 076802 (2014).

    ADS  Article  Google Scholar 

  17. 17

    He, K. et al. Tightly bound excitons in monolayer WSe2 . Phys. Rev. Lett. 113, 026803 (2014).

    ADS  Article  Google Scholar 

  18. 18

    Ye, Z. et al. Probing excitonic dark states in single-layer tungsten disulphide. Nature 513, 214–218 (2014).

    ADS  Article  Google Scholar 

  19. 19

    Ye, J. T. et al. Superconducting dome in a gate-tuned band insulator. Science 338, 1193–1196 (2012).

    ADS  Article  Google Scholar 

  20. 20

    Perkins, F. K. et al. Chemical vapor sensing with monolayer MoS2 . Nano Lett. 13, 668–673 (2013).

    ADS  Article  Google Scholar 

  21. 21

    Wu, W. et al. Peizoelectricity of single-atomic-layer MoS2 for energy conversion and piezotronics. Nature 514, 470–474 (2014).

    ADS  Article  Google Scholar 

  22. 22

    Zhu, H. et al. Observation of piezoelectricity in free-standing monolayer MoS2 . Nature Nanotech. 10, 151–155 (2015).

    ADS  Article  Google Scholar 

  23. 23

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

    ADS  Article  Google Scholar 

  24. 24

    Tamboli, A. C. et al. Room-temperature continuous-wave lasing in GaN/InGaN microdisks. Nature Photon. 1, 61–64 (2007).

    ADS  Article  Google Scholar 

  25. 25

    Schuller, J. A. et al. Orientation of luminescent excitons in layered nanomaterials. Nature Nanotech. 8, 271–276 (2013).

    ADS  Article  Google Scholar 

  26. 26

    Bimberg, D. et al. InGaAs–GaAs quantum-dot lasers. IEEE J. Sel. Topics Quantum Electron. 3, 196–205 (1997).

    ADS  Article  Google Scholar 

  27. 27

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

    Article  Google Scholar 

  28. 28

    Arakawa, Y. & Yariv, A. Quantum well lasers-gain, spectra, dynamics. IEEE J. Sel. Topics Quantum Electron. 22, 1887–1899 (1986).

    ADS  Article  Google Scholar 

  29. 29

    Hendrickson, J. et al. Quantum dot photonic-crystal-slab nanocavities: quality factors and lasing. Phys. Rev. B 72, 193303 (2005).

    ADS  Article  Google Scholar 

  30. 30

    Hsu, K. S. et al. Compact microdisk cavity laser with type-II GaSb/GaAs quantum dots. Appl. Phys. Lett. 98, 051105 (2011).

    ADS  Article  Google Scholar 

  31. 31

    Eichfelder, M. et al. Room-temperature lasing of electrically pumped red-emitting InP/ (Al0.20Ga0.80)0.51In0.49P quantum dots embedded in vertical microcavity. Appl. Phys. Lett. 95, 131107 (2009).

    ADS  Article  Google Scholar 

  32. 32

    Gong, Y. et al. Nanobeam photonic crystal cavity quantum dot laser. Opt. Express 18, 8781–8789 (2010).

    ADS  Article  Google Scholar 

  33. 33

    Mohideen, U. & Slusher, R. E. Semiconductor microlaser linewidths. Phys. Rev. Lett. 73, 1785–1788 (1994).

    ADS  Article  Google Scholar 

  34. 34

    Ammer, F., Penzkofer, A. & Weidner, P. Concentration-dependent fluorescence behavior of oxazine 750 and rhodamine 6G in porous silicate xerogel monoliths. Chem. Phys. 192, 325–331 (1995).

    Article  Google Scholar 

  35. 35

    Wu, S. et al. Monolayer semiconductor nanocavity with ultralow thresholds. Nature 520, 69–72 (2015).

    ADS  Article  Google Scholar 

  36. 36

    Salehzadeh, O., Djavid, M., Tran, N. H., Shih, I. & Mi, Z. Optically pumped two-dimensional MoS2 lasers operating at room-temperature. Nano Lett. 15, 5302–5306 (2015).

    ADS  Article  Google Scholar 

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The authors acknowledge financial support from the US Air Force Office of Scientific Research under award no. FA9550-12-1-0197 (Optical Design and Characterization), and the ‘Light–Material Interaction in Energy Conversion’ Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under award no. DE-AC02-05CH11231 (Materials Synthesis and Lithography). The authors also thank A. Grine for his help in measuring the passive Q factor of the cavity.

Author information




X.Z., Y.W., Y.Y. and Z.J.W. conceived the project. X.L. and X.C. grew bulk WS2 crystals. Y.Y., Z.J.W. and H.Z. developed the sample design and fabricated the samples. Y.Y., Z.J.W. and X.N. performed the measurements. Z.J.W. and Y.Y. performed the numerical simulation. Y.Y. and Z.J.W. carried out the data analysis. Y.Y., Z.J.W., X.Z. and Y.W. wrote the manuscript. X.Z. and Y.W. guided the research. All authors contributed to discussions.

Corresponding author

Correspondence to Xiang Zhang.

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The authors declare no competing financial interests.

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Ye, Y., Wong, Z., Lu, X. et al. Monolayer excitonic laser. Nature Photon 9, 733–737 (2015).

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