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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The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.
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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).
The authors declare no competing interests.
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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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
Acta Mechanica (2021)
Archive of Applied Mechanics (2021)