Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Spontaneous-polarization-induced photovoltaic effect in rhombohedrally stacked MoS2

Abstract

Stacking order in van der Waals materials determines the coupling between atomic layers and is therefore the key to materials’ properties. Recently, ferroelectricity, a phenomenon exhibiting reversible spontaneous electrical polarization, has been observed in zero-degree aligned van der Waals structures. In these artificial stacks, the single-domain size is limited by angle misalignment. Here we show that naturally rhombohedrally stacked MoS2 can host a homogeneous spontaneous polarization throughout the exfoliated flakes, free of misalignment. Utilizing this homogeneous polarization and its induced depolarization field, we build a graphene–MoS2-based photovoltaic device with high efficiency. Few-layer MoS2 is thinner than most oxide-based ferroelectric films, which allows us to maximize the depolarization field and study its impact at the atomically thin limit, whereas the highly uniform polarization in the commensurate crystal enables a tangible path for upscaling. The external quantum efficiency of our device is up to 16% at room temperature, over one order larger than the highest efficiency observed in bulk photovoltaic devices, owing to the reduced screening in graphene, exciton-enhanced light–matter interaction and ultrafast interlayer relaxation. Our findings make rhombohedral transition metal dichalcogenides a promising candidate for applications such as energy-efficient photodetection with high speed and programmable polarity.

Your institute does not have access to this article

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Fig. 1: Crystal structure and electronic band structure of 3R-MoS2 bilayer.
Fig. 2: PC generation in Gr/3R-MoS2/Gr heterostructure.
Fig. 3: Mechanism of PC.
Fig. 4: Scalability of PV effect in 3R-MoS2.

Data availability

Source data are provided with this paper. The data that support the plots within this paper and other findings of this study are available via Zenodo at https://doi.org/10.5281/zenodo.6416128.

Code availability

The codes that support the plots within this paper and other findings of this study are available via Zenodo at https://doi.org/10.5281/zenodo.6416128.

References

  1. Cao, Y. et al. Unconventional superconductivity in magic-angle graphene superlattices. Nature 556, 43–50 (2018).

    ADS  Article  Google Scholar 

  2. Sharpe, A. et al. Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene. Science 365, 605–608 (2019).

    ADS  Article  Google Scholar 

  3. Tang, Y. et al. Simulation of Hubbard model physics in WSe2/WS2 moiré superlattices. Nature 579, 353–358 (2020).

    ADS  Article  Google Scholar 

  4. Regan, E. et al. Mott and generalized Wigner crystal states in WSe2/WS2 moiré superlattices. Nature 579, 359–363 (2020).

    ADS  Article  Google Scholar 

  5. Woods, C. et al. Charge-polarized interfacial superlattices in marginally twisted hexagonal boron nitride. Nat. Commun. 12, 347 (2021).

    Article  Google Scholar 

  6. Yasuda, K., Wang, X., Watanabe, K., Taniguchi, T. & Jarillo-Herrero, P. Stacking-engineered ferroelectricity in bilayer boron nitride. Science 372, 1458–1462 (2021)

  7. Stern, M. et al. Interfacial ferroelectricity by van der Waals sliding. Science 372, 1462–1466 (2021)

  8. Zheng, Z. et al. Unconventional ferroelectricity in moiré heterostructures. Nature 588, 71–76 (2020).

    ADS  Article  Google Scholar 

  9. Tsymbal, E. Two-dimensional ferroelectricity by design. Science 372, 1389–1390 (2021).

    ADS  Article  Google Scholar 

  10. Chen, G. et al. Evidence of a gate-tunable Mott insulator in a trilayer graphene moiré superlattice. Nat. Phys. 15, 237–241 (2019).

    Article  Google Scholar 

  11. Shi, Y. et al. Electronic phase separation in multilayer rhombohedral graphite. Nature 584, 210–214 (2020).

    ADS  Article  Google Scholar 

  12. Zhou, H., Xie, T., Taniguchi, T., Watanabe, K. & Young, A. F. Superconductivity in rhombohedral trilayer graphene. Nature 598, 434–438 (2021).

    ADS  Article  Google Scholar 

  13. Suzuki, R. et al. Valley-dependent spin polarization in bulk MoS2 with broken inversion symmetry. Nat. Nanotechnol. 9, 611–617 (2014).

    Article  Google Scholar 

  14. Zhao, M. et al. Atomically phase-matched second-harmonic generation in a 2D crystal. Light Sci. Appl. 5, e16131 (2016).

    Article  Google Scholar 

  15. Lopez-Varo, P. et al. Physical aspects of ferroelectric semiconductors for photovoltaic solar energy conversion. Phys. Rep. 653, 1–40 (2016).

    ADS  MathSciNet  Article  Google Scholar 

  16. Sipe, J. & Shkrebtii, A. Second-order optical response in semiconductors. Phys. Rev. B 61, 5337 (2000).

    ADS  Article  Google Scholar 

  17. Yang, M., Kim, D. & Alexe, M. Flexo-photovoltaic effect. Science 360, 904–907 (2018).

    ADS  Article  Google Scholar 

  18. Zhang, Y. et al. Enhanced intrinsic photovoltaic effect in tungsten disulfide nanotubes. Nature 570, 349–353 (2019).

    ADS  Article  Google Scholar 

  19. Osterhoudt, G. et al. Colossal mid-infrared bulk photovoltaic effect in a type-I Weyl semimetal. Nat. Mater. 18, 471–475 (2019).

    ADS  Article  Google Scholar 

  20. Akamatsu, T. et al. A van der Waals interface that creates in-plane polarization and a spontaneous photovoltaic effect. Science 372, 68–72 (2021).

    ADS  Article  Google Scholar 

  21. Mehta, R., Silverman, B. & Jacobs, J. Depolarization fields in thin ferroelectric films. J. Appl. Phys. 44, 3379–3385 (1973).

    ADS  Article  Google Scholar 

  22. Qin, M., Yao, K. & Liang, Y. High efficient photovoltaics in nanoscaled ferroelectric thin films. Appl. Phys. Lett. 93, 122904 (2008).

    ADS  Article  Google Scholar 

  23. Yang, S. et al. Above-bandgap voltages from ferroelectric photovoltaic devices. Nat. Nanotechnol. 5, 143–147 (2010).

    ADS  Article  Google Scholar 

  24. Nechache, R. et al. Bandgap tuning of multiferroic oxide solar cells. Nat. Photon. 9, 61–67 (2015).

    ADS  Article  Google Scholar 

  25. Batra, I., Wurfel, P. & Silverman, B. Phase transition, stability, and depolarization field in ferroelectric thin films. Phys. Rev. B 8, 3257 (1973).

    ADS  Article  Google Scholar 

  26. Wurfel, P. & Batra, I. Depolarization-field-induced instability in thin ferroelectric films—experiment and theory. Phys. Rev. B 8, 5126 (1973).

    ADS  Article  Google Scholar 

  27. Fong, D. et al. Ferroelectricity in ultrathin perovskite films. Science 304, 1650–1653 (2004).

    ADS  Article  Google Scholar 

  28. Qin, M., Yao, K. & Liang, Y. Photovoltaic mechanisms in ferroelectric thin films with the effects of the electrodes and interfaces. Appl. Phys. Lett. 95, 022912 (2009).

    ADS  Article  Google Scholar 

  29. Wang, Y., Wang, Z., Yao, W., Liu, G. & Yu, H. Interlayer coupling in commensurate and incommensurate bilayer structures of transition-metal dichalcogenides. Phys. Rev. B 95, 115429 (2017).

    ADS  Article  Google Scholar 

  30. Andersen, T. et al. Excitons in a reconstructed moiré potential in twisted WSe2/WSe2 homobilayers. Nat. Mater. 20, 480–487 (2021)

  31. Sung, J. et al. Broken mirror symmetry in excitonic response of reconstructed domains in twisted MoSe2/MoSe2 bilayers. Nat. Nanotechnol. 15, 750–754 (2020).

    ADS  Article  Google Scholar 

  32. Kormányos, A., Zólyomi, V., Fal’ko, V. & Burkard, G. Tunable Berry curvature and valley and spin Hall effect in bilayer MoS2. Phys. Rev. B 98, 035408 (2018).

    ADS  Article  Google Scholar 

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

    ADS  Article  Google Scholar 

  34. Yu, W. et al. Highly efficient gate-tunable photocurrent generation in vertical heterostructures of layered materials. Nat. Nanotechnol. 8, 952–958 (2013).

    ADS  Article  Google Scholar 

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

    ADS  Article  Google Scholar 

  36. Gregg, B. Excitonic solar cells. J. Phys. Chem. B 107, 4688–4698 (2003).

    Article  Google Scholar 

  37. Ju, L. et al. Topological valley transport at bilayer graphene domain walls. Nature 520, 650–655 (2015).

    ADS  Article  Google Scholar 

  38. Britnell, L. et al. Field-effect tunneling transistor based on vertical graphene heterostructures. Science 335, 947–950 (2012).

    ADS  Article  Google Scholar 

  39. Xu, X., Gabor, N., Alden, J., Van Der Zande, A. & McEuen, P. Photo-thermoelectric effect at a graphene interface junction. Nano Lett. 10, 562–566 (2010).

    ADS  Article  Google Scholar 

  40. Freitag, M., Low, T., Xia, F. & Avouris, P. Photoconductivity of biased graphene. Nat. Photon. 7, 53–59 (2013).

    ADS  Article  Google Scholar 

  41. Koppens, F. et al. Photodetectors based on graphene, other two-dimensional materials and hybrid systems. Nat. Nanotechnol. 9, 780–793 (2014).

    ADS  Article  Google Scholar 

  42. Park, J. et al. Optical control of the layer degree of freedom through Wannier–Stark states in polar 3R MoS2. J. Phys.: Condens. Matter 31, 315502 (2019).

    Google Scholar 

  43. Yu, W. et al. Unusually efficient photocurrent extraction in monolayer van der Waals heterostructure by tunnelling through discretized barriers. Nat. Commun. 7, 13278 (2016).

    ADS  Article  Google Scholar 

  44. Jin, C. et al. Ultrafast dynamics in van der Waals heterostructures. Nat. Nanotechnol. 13, 994–1003 (2018).

    ADS  Article  Google Scholar 

  45. Lee, C. et al. Atomically thin p–n junctions with van der Waals heterointerfaces. Nat. Nanotechnol. 9, 676–681 (2014).

    Google Scholar 

  46. Mak, K. & Shan, J. Photonics and optoelectronics of 2D semiconductor transition metal dichalcogenides. Nat. Photon. 10, 216–226 (2016).

    ADS  Article  Google Scholar 

  47. Wang, G. et al. Colloquium: excitons in atomically thin transition metal dichalcogenides. Rev. Mod. Phys. 90, 021001 (2018).

    ADS  MathSciNet  Article  Google Scholar 

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

    ADS  Article  Google Scholar 

  49. Ju, L. et al. Photoinduced doping in heterostructures of graphene and boron nitride. Nat. Nanotechnol. 9, 348–352 (2014).

    ADS  Article  Google Scholar 

Download references

Acknowledgements

Z.Y., D.Y., J.W., J.L., B.T.Z., M.F., T.S. and K.M.A. acknowledge support from the Natural Sciences and Engineering Research Council of Canada, Canada Foundation for Innovation, New Frontiers in Research Fund, Canada First Research Excellence Fund and Max Planck-UBC-UTokyo Centre for Quantum Materials. Z.Y. is also supported by the Canada Research Chairs Program. B.T.Z. and M.F. acknowledge Quantum Materials and Future Technologies Program, and the Croucher Foundation. Y.I. acknowledges support from JSPS Grant-in-Aid for Scientific Research (S) (JP19H05602) and the A3 Foresight Program. T.I. acknowledges Grant-in-Aid for Scientific Research on Innovative Areas (JP20H05264), Grant-in-Aid for Scientific Research (B) (JP19H01819) and JST PRESTO (JPMJPR19L1). K.W. and T.T. acknowledge support from JSPS KAKENHI (grant nos. 19H05790, 20H00354 and 21H05233). We would like to thank J. Dadap, Z. Wang, J. Folk, D. Jones, G. Sawatzky, A. Damascelli and T. Cao for helpful discussion.

Author information

Authors and Affiliations

Authors

Contributions

Z.Y. and D.Y. conceived this work. D.Y., T.S., J.W. and K.M.A. fabricated the sample. D.Y., J.W. and J.L. conducted the measurement under supervision from Z.Y. B.T.Z. performed the theoretical calculation under supervision from M.F. and Z.Y. T.I., Y.I., K.W. and T.T. provided the bulk crystal. Z.Y., D.Y. and J.W. analysed the data. Z.Y. and D.Y. wrote the manuscript based on inputs from all the other authors.

Corresponding author

Correspondence to Ziliang Ye.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Photonics thanks the anonymous reviewers for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Thermal Background of Photocurrent.

Extracted thermal contributions of the AB (top panel) and BA (bottom panel) domains. The straight lines with negative slopes are due to the bolometric effect IBOL, which crosses zero at zero bias. The non-zero intercept is caused by the photo-thermal electric effect IPTE, which is opposite in direction to IPV. The IPTE is approximately independent with bias.

Source data

Extended Data Fig. 2 Photocurrent I-V curve of 2H Bilayer.

Bias dependence of photocurrent in the 2H bilayer device, C1. With a similar laser illumination condition (P=20 μW), C1 shows a nearly zero photocurrent at zero bias. The photocurrent linearly increases with bias, with no thermal contribution observed.

Source data

Supplementary information

Supplementary Information

Supplementary Figs. 1–11, Sections 1–15 and refs. 1–29.

Reporting Summary

Source data

Source Data Fig. 1

Experimental source data.

Source Data Fig. 2

Experimental source data.

Source Data Fig. 3

Experimental source data.

Source Data Fig. 4

Simulation results and experimental source data.

Source Data Extended Data Fig. 1

Extracted data from the global fitting in Fig. 3.

Source Data Extended Data Fig. 2

Experimental source data.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Yang, D., Wu, J., Zhou, B.T. et al. Spontaneous-polarization-induced photovoltaic effect in rhombohedrally stacked MoS2. Nat. Photon. 16, 469–474 (2022). https://doi.org/10.1038/s41566-022-01008-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41566-022-01008-9

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing