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Giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor


Two-dimensional (2D) transition metal dichalcogenides (TMDs) are emerging as a new platform for exploring 2D semiconductor physics1,2,3,4,5,6,7,8,9. Reduced screening in two dimensions results in markedly enhanced electron–electron interactions, which have been predicted to generate giant bandgap renormalization and excitonic effects10,11,12,13. Here we present a rigorous experimental observation of extraordinarily large exciton binding energy in a 2D semiconducting TMD. We determine the single-particle electronic bandgap of single-layer MoSe2 by means of scanning tunnelling spectroscopy (STS), as well as the two-particle exciton transition energy using photoluminescence (PL) spectroscopy. These yield an exciton binding energy of 0.55 eV for monolayer MoSe2 on graphene—orders of magnitude larger than what is seen in conventional 3D semiconductors and significantly higher than what we see for MoSe2 monolayers in more highly screening environments. This finding is corroborated by our ab initio GW and Bethe–Salpeter equation calculations14,15 which include electron correlation effects. The renormalized bandgap and large exciton binding observed here will have a profound impact on electronic and optoelectronic device technologies based on single-layer semiconducting TMDs.

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Figure 1: Morphology of monolayer MoSe2 on bilayer graphene.
Figure 2: Electronic structure of monolayer MoSe2 on bilayer graphene.
Figure 3: Optical characterization of monolayer MoSe2 on bilayer graphene.
Figure 4: Comparison between ab initio excited-state calculations and single-layer MoSe2 experiment.


  1. Mak, K. F. et al. Atomically thin MoS2: A new direct-gap semiconductor. Phys. Rev. Lett. 105, 136805 (2010).

    Article  Google Scholar 

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

    Article  CAS  Google Scholar 

  3. Mak, K. F., He, K. L., 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 

  4. Zeng, H. L. et al. Valley polarization in MoS2 monolayers by optical pumping. Nature Nanotech. 7, 490–493 (2012).

    Article  CAS  Google Scholar 

  5. Cao, T. et al. Valley-selective circular dichroism of monolayer molybdenum disulphide. Nature Commun. 3, 1882 (2012).

    Google Scholar 

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

    Article  CAS  Google Scholar 

  7. Britnell, L. et al. Strong light–matter interactions in heterostructures of atomically thin films. Science 340, 1311–1314 (2013).

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  9. Zhang, Y. et al. Direct observation of the transition from indirect to direct band gap in atomically-thin epitaxial MoSe2 . Nature Nanotech. 9, 111–115 (2014).

    Article  CAS  Google Scholar 

  10. Cheiwchanchamnangij, T. & Lambrecht, W. R. L. Quasiparticle band structure calculation of monolayer, bilayer, and bulk MoS2 . Phys. Rev. B 85, 205302 (2012).

    Article  Google Scholar 

  11. Ramasubramaniam, A. Large excitonic effects in monolayers of molybdenum and tungsten dichalcogenides. Phys. Rev. B 86, 115409 (2012).

    Article  Google Scholar 

  12. Komsa, H. P. & Krasheninnikov, A. V. Effects of confinement and environment on the electronic structure and exciton binding energy of MoS2 from first principles. Phys. Rev. B 86, 241201 (2012).

    Article  Google Scholar 

  13. Qiu, D. Y., da Jornada, F. H. & Louie, S. G. Optical spectrum of MoS2: Many-body effects and diversity of exciton states. Phys. Rev. Lett. 111, 216805 (2013).

    Article  Google Scholar 

  14. Hybertsen, M. S. & Louie, S. G. Electron correlation in semiconductors and insulators: band-gaps and quasi-particle energies. Phys. Rev. B 34, 5390–5413 (1986).

    Article  CAS  Google Scholar 

  15. Rohlfing, M. & Louie, S. G. Electron–hole excitations and optical spectra from first principles. Phys. Rev. B 62, 4927–4944 (2000).

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  17. Bernardi, M., Palummo, M. & Grossman, J. C. Extraordinary sunlight absorption and one nanometer thick photovoltaics using two-dimensional monolayer materials. Nano Lett. 13, 3664–3670 (2013).

    Article  CAS  Google Scholar 

  18. Gutierrez, H. R. et al. Extraordinary room-temperature photoluminescence in triangular WS2 monolayers. Nano Lett. 13, 3447–3454 (2013).

    Article  CAS  Google Scholar 

  19. Wang, F., Dukovic, G., Brus, L. E. & Heinz, T. F. The optical resonances in carbon nanotubes arise from excitons. Science 308, 838–841 (2005).

    Article  CAS  Google Scholar 

  20. Scholes, G. D. & Rumbles, G. Excitons in nanoscale systems. Nature Mater. 5, 683–696 (2006).

    Article  CAS  Google Scholar 

  21. Mallet, P. et al. Electron states of mono- and bilayer graphene on SiC probed by scanning-tunneling microscopy. Phys. Rev. B 76, 041403 (2007).

    Article  Google Scholar 

  22. Hor, Y. S. et al. p-type Bi2Se3 for topological insulator and low-temperature thermoelectric applications. Phys. Rev. B 79, 195208 (2009).

    Article  Google Scholar 

  23. Feenstra, R. M. & Stroscio, J. A. Tunneling spectroscopy of the GaAs(110) surface. J. Vac. Sci. Technol. B 5, 923–929 (1987).

    Article  CAS  Google Scholar 

  24. Ross, J. S. et al. Electrical control of neutral and charged excitons in a monolayer semiconductor. Nature Commun. 4, 2498 (2013).

    Article  Google Scholar 

  25. Deslippe, J. et al. BerkeleyGW: A massively parallel computer package for the calculation of the quasiparticle and optical properties of materials and nanostructures. Comput. Phys. Commun. 183, 1269–1289 (2012).

    Article  CAS  Google Scholar 

  26. Lischner, J., Vigil-Fowler, D. & Louie, S. G. Physical origin of satellites in photoemission of doped graphene: An ab Initio GW plus cumulant study. Phys. Rev. Lett. 110, 146801 (2013).

    Article  Google Scholar 

  27. Helveg, S. et al. Atomic-scale structure of single-layer MoS2 nanoclusters. Phys. Rev. Lett. 84, 951–954 (2000).

    Article  CAS  Google Scholar 

  28. Zhang, C. et al. Direct imaging of band profile in single layer MoS2 on graphite: Quasiparticle energy gap, metallic edge states, and edge band bending. Nano Lett. 14, 2443–2447 (2014).

    Article  CAS  Google Scholar 

  29. Brar, V. W. et al. Scanning tunneling spectroscopy of inhomogeneous electronic structure in monolayer and bilayer graphene on SiC. Appl. Phys. Lett. 91, 122102 (2007).

    Article  Google Scholar 

  30. Mallet, P. et al. Role of pseudospin in quasiparticle interferences in epitaxial graphene probed by high-resolution scanning tunneling microscopy. Phys. Rev. B 86, 045444 (2012).

    Article  Google Scholar 

  31. Horcas, I. et al. WSXM: A software for scanning probe microscopy and a tool for nanotechnology. Rev. Sci. Instrum. 78, 013705 (2007).

    Article  CAS  Google Scholar 

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Research supported by Office of Basic Energy Sciences, Department of Energy Early Career Award No. DE-SC0003949 (optical measurements), and by the sp2 Program (STM instrumentation development and operation), the Theory Program (GW–BSE calculations), and the SciDAC Program on Excited State Phenomena in Energy Materials (algorithms and codes) which are funded by the US Department of Energy, Office of Basic Energy Sciences and of Advanced Scientific Computing Research, under Contract No. DE-AC02-05CH11231. Support also provided by National Science Foundation award no. 1235361 (image analysis) and National Science Foundation award no. DMR10-1006184 (substrate screening theory and calculations). Computational resources have been provided by the NSF through XSEDE resources at NICS and DOE at NERSC. A.J.B. was supported by the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program. W. R acknowledges support from the Chinese Scholarship Council (No. 201306210202). D.Y.Q. acknowledges support from NSF Graduate Research Fellowship Grant No. DGE 1106400 and S.G.L. acknowledges support of a Simons Foundation Fellowship in Theoretical Physics. STM/STS data were analysed and rendered using WSxM software31. S-F.S. and F.W. acknowledge X. Hong and J. Kim for technical help.

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M.M.U., A.J.B., S-F.S., F.W. and M.F.C. conceived the work and designed the research strategy. M.M.U. and A.J.B. measured and analysed the STM/STS data in collaboration with W.R. for the MoSe2/HOPG experiments. S-F.S. carried out the photoluminescence and Raman experiments. F.H.d.J. and D.Y.Q. performed the theoretical calculations. Y.Z. and S-K.M. performed the MBE growth and characterization (LEED, RHEED, core-level spectroscopy) of the samples. Z.H. and Z-X.S. supervised the MBE and sample characterization. F.W. supervised the optical measurements. S.G.L. supervised the theoretical calculations. M.F.C. supervised the STM/STS experiments. M.M.U. wrote the paper with help from A.J.B. and M.F.C. M.M.U. and M.F.C. coordinated the collaboration. All authors contributed to the scientific discussion and manuscript revisions.

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Correspondence to Miguel M. Ugeda or Michael F. Crommie.

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Ugeda, M., Bradley, A., Shi, SF. et al. Giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor. Nature Mater 13, 1091–1095 (2014).

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