Flexoelectronics of centrosymmetric semiconductors

Abstract

Interface engineering by local polarization using piezoelectric1,2,3,4, pyroelectric5,6 and ferroelectric7,8,9 effects has attracted considerable attention as a promising approach for tunable electronics/optoelectronics, human–machine interfacing and artificial intelligence. However, this approach has mainly been applied to non-centrosymmetric semiconductors, such as wurtzite-structured ZnO and GaN, limiting its practical applications. Here we demonstrate an electronic regulation mechanism, the flexoelectronics, which is applicable to any semiconductor type, expanding flexoelectricity10,11,12,13 to conventional semiconductors such as Si, Ge and GaAs. The inner-crystal polarization potential generated by the flexoelectric field serving as a ‘gate’ can be used to modulate the metal–semiconductor interface Schottky barrier and further tune charge-carrier transport. We observe a giant flexoelectronic effect in bulk centrosymmetric semiconductors of Si, TiO2 and Nb–SrTiO3 with high strain sensitivity (>2,650), largely outperforming state-of-the-art Si-nanowire strain sensors and even piezoresistive, piezoelectric and ferroelectric nanodevices14. The effect can be used to mechanically switch the electronics in the nanoscale with fast response (<4 ms) and high resolution (~0.78 nm). This opens up the possibility of realizing strain-modulated electronics in centrosymmetric semiconductors, paving the way for local polarization field-controlled electronics and high-performance electromechanical applications.

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Fig. 1: The mechanism of flexoelectronics.
Fig. 2: Flexoelectronic effect in low-doped p-Si single crystal.
Fig. 3: Electronic transport in other types of silicon under nanoindentation.
Fig. 4: Flexoelectronic effect in ionic semiconductors.
Fig. 5: Demonstration of flexoelectronics by mechanical 2D scanning.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

References

  1. 1.

    Wu, W. Z., Wen, X. N. & Wang, Z. L. Taxel-addressable matrix of vertical-nanowire piezotronic transistors for active and adaptive tactile imaging. Science 340, 952–957 (2013).

    CAS  Google Scholar 

  2. 2.

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

    CAS  Google Scholar 

  3. 3.

    Pan, C. F. et al. High-resolution electroluminescent imaging of pressure distribution using a piezoelectric nanowire LED array. Nat. Photon. 7, 752–758 (2013).

    CAS  Google Scholar 

  4. 4.

    Qi, J. J. et al. Piezoelectric effect in chemical vapour deposition-grown atomic-monolayer triangular molybdenum disulfide piezotronics. Nat. Commun. 6, 7430 (2015).

    CAS  Google Scholar 

  5. 5.

    Stewart, J. W., Vella, J. H., Li, W., Fan, S. & Mikkelsen, M. H. Ultrafast pyroelectric photodetection with on-chip spectral filters. Nat. Mater. 19, 158–162 (2019).

    Google Scholar 

  6. 6.

    Wang, Z., Yu, R., Pan, C., Li, Z., Yang, J., Yi, F. & Wang, Z. L. Light-induced pyroelectric effect as an effective approach for ultrafast ultraviolet nanosensing. Nat. Commun. 6, 8401 (2015).

    CAS  Google Scholar 

  7. 7.

    Maksymovych, P., Jesse, S., Yu, P., Ramesh, R., Baddorf, A. P. & Kalinin, S. V. Polarization control of electron tunneling into ferroelectric surfaces. Science 324, 1421–1425 (2009).

    CAS  Google Scholar 

  8. 8.

    Garcia, V. et al. Ferroelectric control of spin polarization. Science 327, 1106–1110 (2010).

    CAS  Google Scholar 

  9. 9.

    Zhang, Y. et al. Anisotropic polarization-induced conductance at a ferroelectric–insulator interface. Nat. Nanotechnol. 13, 1132–1136 (2018).

    CAS  Google Scholar 

  10. 10.

    Kogan, S. M. Piezoelectric effect during inhomogeneous deformation and acoustic scattering of carriers in crystals. Sov. Phys. Solid State 5, 2069–2070 (1964).

    Google Scholar 

  11. 11.

    Bursian, E. & Zaikovskii, O. I. Changes in curvature of ferroelectric film due to polarization. Sov. Phys. Solid State 10, 1121 (1968).

    Google Scholar 

  12. 12.

    Catalan, G. et al. Flexoelectric rotation of polarization in ferroelectric thin films. Nat. Mater. 10, 963–967 (2011).

    CAS  Google Scholar 

  13. 13.

    Lu, H. et al. Mechanical writing of ferroelectric polarization. Science 336, 59–61 (2012).

    CAS  Google Scholar 

  14. 14.

    Trung, T. Q. & Lee, N. E. Flexible and stretchable physical sensor integrated platforms for wearable human-activity monitoring and personal healthcare. Adv. Mater. 28, 4338–4372 (2016).

    CAS  Google Scholar 

  15. 15.

    Bhaskar, U. K., Banerjee, N., Abdollahi, A., Wang, Z., Schlom, D. G., Rijnders, G. & Catalan, G. A flexoelectric microelectromechanical system on silicon. Nat. Nanotechnol. 11, 263–266 (2016).

    CAS  Google Scholar 

  16. 16.

    Wen, X., Li, D., Tan, K., Deng, Q. & Shen, S. P. Flexoelectret: an electret with a tunable flexoelectriclike response. Phys. Rev. Lett. 122, 148001 (2019).

    CAS  Google Scholar 

  17. 17.

    Das, S. et al. Enhanced flexoelectricity at reduced dimensions revealed by mechanically tunable quantum tunneling. Nat. Commun. 10, 537 (2019).

    CAS  Google Scholar 

  18. 18.

    Narvaez, J., Vasquez-Sancho, F. & Catalan, G. Enhanced flexoelectric-like response in oxide semiconductors. Nature 538, 219–221 (2016).

    CAS  Google Scholar 

  19. 19.

    Wang, Z. L. Nanopiezotronics. Adv. Mater. 19, 889–892 (2007).

    CAS  Google Scholar 

  20. 20.

    Wu, W. Z. & Wang, Z. L. Piezotronics and piezo-phototronics for adaptive electronics and optoelectronics. Nat. Rev. Mater. 1, 16031 (2016).

    CAS  Google Scholar 

  21. 21.

    Zhang, Y., Liu, Y. & Wang, Z. L. Fundamental theory of piezotronics. Adv. Mater. 23, 3004–3013 (2011).

    CAS  Google Scholar 

  22. 22.

    Wang, Z. L. & Wu, W. Z. Piezotronics and piezo-phototronics: fundamentals and applications. Natl Sci. Rev. 1, 62–90 (2014).

    CAS  Google Scholar 

  23. 23.

    Fischer-Cripps, A. C Introduction to Contact Mechanics (Springer, 2000).

  24. 24.

    Zubko, P., Catalan, G., Buckley, A., Welche, P. R. L. & Scott, J. F. Strain-gradient-induced polarization in SrTiO3 single crystal. Phys. Rev. Lett. 99, 167601 (2007).

    CAS  Google Scholar 

  25. 25.

    Hong, J. W. & Vanderbilt, D. First-principles theory and calculation of flexoelectricity. Phys. Rev. B 88, 174107 (2013).

    Google Scholar 

  26. 26.

    Amjadi, M., Kyung, K. U., Park, I. & Sitti, M. Stretchable, skin-mountable, and wearable strain sensors and their potential applications: a review. Adv. Funct. Mater. 26, 1678–1698 (2016).

    CAS  Google Scholar 

  27. 27.

    Conley, H. J. et al. Bandgap engineering of strained monolayer and bilayer MoS2. Nano Lett. 13, 3626–3630 (2013).

    CAS  Google Scholar 

  28. 28.

    Gao, Y. & Wang, Z. L. Equilibrium potential of free charge carriers in a bent piezoelectric semiconductive nanowire. Nano Lett. 9, 1103–1110 (2009).

    CAS  Google Scholar 

  29. 29.

    Park, S. M. et al. Selective control of multiple ferroelectric switching pathways using a trailing flexoelectric field. Nat. Nanotechnol. 13, 366–370 (2018).

    CAS  Google Scholar 

  30. 30.

    Chu, K. et al. Enhancement of the anisotropic photocurrent in ferroelectric oxides by strain gradients. Nat. Nanotechnol. 10, 972–979 (2015).

    CAS  Google Scholar 

  31. 31.

    Landau, L. D., Pitaevskii L. P., Kosevich, A. M., Lifshitz, E.M. Theory of Elasticity (Elsevier, 1986).

  32. 32.

    Yudin, P. V. & Tagantsev, A. K. Fundamentals of flexoelectricity in solids. Nanotechnology 24, 432001 (2013).

    CAS  Google Scholar 

  33. 33.

    Očenášek, J. et al. Nanomechanics of flexoelectric switching. Phys. Rev. B 92, 035417 (2015).

    Google Scholar 

  34. 34.

    Zubko, P., Catalan, G. & Tagantsev, K. T. Flexoelectric effect in solids. Annu. Rev. Mater. Res. 43, 387–421 (2013).

    CAS  Google Scholar 

  35. 35.

    Eliseev, E. A. & Morozovska, A. N. Hidden symmetry of flexoelectric coupling. Phys. Rev. B 98, 094108 (2018).

    CAS  Google Scholar 

Download references

Acknowledgements

We thank Q. Xu and S. Xu for helpful discussion. This research was supported by the National Key R&D Project from Minister of Science and Technology (grant number 2016YFA0202704), Beijing Municipal Science and Technology Commission (grant numbers Z171100000317001, Z171100002017017, Y3993113DF) and the National Natural Science Foundation of China (grant numbers 11704032, 51432005, 5151101243, 51561145021, 51322203 and 51472111).

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Z.L.W., L.W., Y.Q. and S.L conceived the project. Z.L.W., L.W., Y.Q. and S.L. designed the experiments. L.W. and S.L. performed the experiments and analysed the results. X.F and C.Z performed the theoretical calculations and analysis. L.Z and J.Z provided assistance with the experiments. All authors contributed to discussions and to writing the manuscript.

Corresponding authors

Correspondence to Yong Qin or Zhong Lin Wang.

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The authors declare no competing interests.

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Peer review information Nature Nanotechnology thanks Shanming Ke and Sang-Woo Kim for their contribution to the peer review of this work.

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Supplementary Information

Supplementary Notes 1–8, Figs. 1–26, Tables 1–4 and refs 1–72.

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Wang, L., Liu, S., Feng, X. et al. Flexoelectronics of centrosymmetric semiconductors. Nat. Nanotechnol. 15, 661–667 (2020). https://doi.org/10.1038/s41565-020-0700-y

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