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High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe

Abstract

A decade of intense research on two-dimensional (2D) atomic crystals has revealed that their properties can differ greatly from those of the parent compound1,2. These differences are governed by changes in the band structure due to quantum confinement and are most profound if the underlying lattice symmetry changes3,4. Here we report a high-quality 2D electron gas in few-layer InSe encapsulated in hexagonal boron nitride under an inert atmosphere. Carrier mobilities are found to exceed 103 cm2 V−1 s−1 and 104 cm2 V−1 s−1 at room and liquid-helium temperatures, respectively, allowing the observation of the fully developed quantum Hall effect. The conduction electrons occupy a single 2D subband and have a small effective mass. Photoluminescence spectroscopy reveals that the bandgap increases by more than 0.5 eV with decreasing the thickness from bulk to bilayer InSe. The band-edge optical response vanishes in monolayer InSe, which is attributed to the monolayer's mirror-plane symmetry. Encapsulated 2D InSe expands the family of graphene-like semiconductors and, in terms of quality, is competitive with atomically thin dichalcogenides5,6,7 and black phosphorus8,9,10,11.

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Figure 1: 2D InSe devices.
Figure 2: Transport properties of atomically thin InSe.
Figure 3: Magnetotransport in few-layer InSe.
Figure 4: Photoluminescence from 2D InSe.

References

  1. 1

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

    CAS  Article  Google Scholar 

  2. 2

    Geim, A. K. & Grigorieva, I. V. Van der Waals heterostructures. Nature 499, 419–425 (2013).

    CAS  Article  Google Scholar 

  3. 3

    Castro Neto, A. H., Peres, N. M. R., Novoselov, K. S. & Geim, A. K. The electronic properties of graphene. Rev. Mod. Phys. 81, 109–162 (2009).

    CAS  Article  Google Scholar 

  4. 4

    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 

  5. 5

    Cui, X. et al. Multi-terminal transport measurements of MoS2 using a van der Waals heterostructure device platform. Nat. Nanotech. 10, 534–540 (2015).

    CAS  Article  Google Scholar 

  6. 6

    Fallahazad, B. et al. Shubnikov–de Haas oscillations of high-mobility holes in monolayer and bilayer WSe2: Landau level degeneracy, effective mass, and negative compressibility. Phys. Rev. Lett. 116, 086601 (2016).

    Article  Google Scholar 

  7. 7

    Xu, S. et al. Universal low-temperature ohmic contacts for quantum transport in transition metal dichalcogenides. 2D Mater. 3, 021007 (2016).

    Article  Google Scholar 

  8. 8

    Tayari, V. et al. Two-dimensional magnetotransport in a black phosphorus naked quantum well. Nat. Commun. 6, 7702 (2015).

    CAS  Article  Google Scholar 

  9. 9

    Li, L. et al. Quantum oscillations in a two-dimensional electron gas in black phosphorus thin films. Nat. Nanotech. 10, 608–613 (2015).

    CAS  Article  Google Scholar 

  10. 10

    Gillgren, N. et al. Gate tunable quantum oscillations in air-stable and high mobility few-layer phosphorene heterostructures. 2D Mater. 2, 011001 (2014).

    Article  Google Scholar 

  11. 11

    Li, L. et al. Quantum Hall effect in black phosphorus two-dimensional electron system. Nat. Nanotech. 11, 6–10 (2016).

    Article  Google Scholar 

  12. 12

    Kuroda, N. & Nishina, Y. Resonance Raman scattering study on exciton and polaron anisotropies in InSe. Solid State Commun. 34, 481–484 (1980).

    CAS  Article  Google Scholar 

  13. 13

    Kress-Rogers, E., Nicholas, R. J., Portal, J. C. & Chevy, A. Cyclotron resonance studies on bulk and two-dimensional conduction electrons in InSe. Solid State Commun. 44, 379–383 (1982).

    CAS  Article  Google Scholar 

  14. 14

    Segura, A., Pomer, F., Cantarero, A., Krause, W. & Chevy, A. Electron scattering mechanisms in n-type indium selenide. Phys. Rev. B 29, 5708–5717 (1984).

    CAS  Article  Google Scholar 

  15. 15

    Camassel, J., Merle, P., Mathieu, H. & Chevy, A. Excitonic absorption edge of indium selenide. Phys. Rev. B 17, 4718–4725 (1978).

    CAS  Article  Google Scholar 

  16. 16

    Lei, S. et al. Evolution of the electronic band structure and efficient photo-detection in atomic layers of InSe. ACS Nano 8, 1263–1272 (2014).

    CAS  Article  Google Scholar 

  17. 17

    Mudd, G. W. et al. Tuning the bandgap of exfoliated InSe nanosheets by quantum confinement. Adv. Mater. 25, 5714–5718 (2013).

    CAS  Article  Google Scholar 

  18. 18

    Brotons-Gisbert, M. et al. Nanotexturing to enhance photoluminescent response of atomically thin indium selenide with highly tunable band gap. Nano Lett. 16, 3221–3229 (2016).

    CAS  Article  Google Scholar 

  19. 19

    Zolyomi, V., Drummond, N. D. & Fal'ko, V. I. Electrons and phonons in single layers of hexagonal indium chalcogenides from ab initio calculations. Phys. Rev. B 89, 1–8 (2014).

    Article  Google Scholar 

  20. 20

    Feng, W. et al. Ultrahigh photo-responsivity and detectivity in multilayer InSe nanosheets phototransistors with broadband response. J. Mater. Chem. C 3, 7022–7028 (2015).

    CAS  Article  Google Scholar 

  21. 21

    Mudd, G. W. et al. High broad-band photoresponsivity of mechanically formed InSe–graphene van der Waals heterostructures. Adv. Mater. 27, 3760–3766 (2015).

    CAS  Article  Google Scholar 

  22. 22

    Tamalampudi, S. R. et al. High performance and bendable few-layered InSe photodetectors with broad spectral response. Nano Lett. 14, 2800–2806 (2014).

    CAS  Article  Google Scholar 

  23. 23

    Feng, W., Zheng, W., Cao, W. & Hu, P. Back gated multilayer InSe transistors with enhanced carrier mobilities via the suppression of carrier scattering from a dielectric interface. Adv. Mater. 26, 6587–6593 (2014).

    CAS  Article  Google Scholar 

  24. 24

    Sucharitakul, S. et al. Intrinsic electron mobility exceeding 103 cm2/Vs in multilayer InSe FETs. Nano Lett. 15, 3815–3819 (2015).

    CAS  Article  Google Scholar 

  25. 25

    Kress-Rogers, E. et al. The electric sub-band structure of electron accumulation layers in InSe from Shubnikov–de Haas oscillations and inter-sub-band resonance. J. Phys. C 16, 4285–4295 (2000).

    Article  Google Scholar 

  26. 26

    Wang, L. et al. One-dimensional electrical contact to a two-dimensional material. Science 342, 614–617 (2013).

    CAS  Article  Google Scholar 

  27. 27

    Kretinin, A. V. et al. Electronic properties of graphene encapsulated with different two-dimensional atomic crystals. Nano Lett. 14, 3270–3276 (2014).

    CAS  Article  Google Scholar 

  28. 28

    Cao, Y. et al. Quality heterostructures from two-dimensional crystals unstable in air by their assembly in inert atmosphere. Nano Lett. 15, 4914–4921 (2015).

    CAS  Article  Google Scholar 

  29. 29

    Sun, C . et al. Ab initio study of carrier mobility of few-layer InSe. Appl. Phys. Express 9, 035203 (2016).

    Article  Google Scholar 

  30. 30

    Castellanos-Gomez, A. Why all the fuss about 2D semiconductors? Nat. Photon. 10, 202–204 (2016).

    CAS  Article  Google Scholar 

  31. 31

    Favron, A. et al. Photooxidation and quantum confinement effects in exfoliated black phosphorus. Nat. Mater. 14, 826–832 (2015).

    CAS  Article  Google Scholar 

Download references

Acknowledgements

This work was supported by the European Research Council, the Graphene Flagship, the Engineering and Physical Sciences Research Council (EPSRC, UK) and The Royal Society. D.A.B. and I.V.G. acknowledge support from the Marie Curie programme SPINOGRAPH (Spintronics in Graphene). A.M. acknowledges support of the EPSRC Early Career Fellowship EP/N007131/1. S.V.M. was supported by the NUST MISiS (grant K1-2015-046) and the Russian Foundation for Basic Research (RFBR15-02-01221 and RFBR14-02-00792). V.F. acknowledges support from the ERC Synergy Grant Hetero2D, the EPSRC grant EP/N010345/1 and the Lloyd Register Foundation Nanotechnology grant, and V.Z. from the European Graphene Flagship Project. Measurements in high magnetic field were supported by the High Field Magnet Laboratory–Radboud University/Foundation for Fundamental Research on Matter, member of the European Magnetic Field Laboratory, and by the EPSRC via its membership to the EMFL (grant EP/N01085X/1). We thank M. Mohammed for assisting with UV PL measurements.

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D.A.B., G.L.Y., R.K.K., A.M. and S.V.M. performed transport measurements and A.V.T. carried out optical studies. D.A.B. and A.V.T. analysed experimental data with help from A.K.G. and V.I.F. Y.C. fabricated devices and co-supervised the project with help from R.V.G. V.Z. and V.I.F. provided theory support. Z.R.K., Z.D.K. and A.P. provided bulk InSe crystals. D.A.B., V.I.F. and A.K.G. wrote the manuscript. All authors contributed to discussions.

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Correspondence to Andre K. Geim or Yang Cao.

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The authors declare no competing financial interests.

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Bandurin, D., Tyurnina, A., Yu, G. et al. High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe. Nature Nanotech 12, 223–227 (2017). https://doi.org/10.1038/nnano.2016.242

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