Out-of-Plane Piezoelectricity and Ferroelectricity in Layered α-In2Se3 Nanoflakes

Zhou, Yu; Wu, Di; Zhu, Yihan; Cho, Yujin; He, Qing; Yang, Xiao; Herrera, Kevin; Chu, Zhaodong; Han, Yu; Downer, Michael C.; Peng, Hailin; Lai, Keji

doi:10.1021/acs.nanolett.7b02198

Out-of-Plane Piezoelectricity and Ferroelectricity in Layered α-In2Se3 Nanoflakes

Zhou, Yu; Wu, Di; Zhu, Yihan; Cho, Yujin; He, Qing; Yang, Xiao; Herrera, Kevin; Chu, Zhaodong; Han, Yu; Downer, Michael C.; Peng, Hailin; Lai, Keji

Authors

Yu Zhou

Di Wu

Yihan Zhu

Yujin Cho

Dr Helen He qing.he@durham.ac.uk
Assistant Professor

Xiao Yang

Kevin Herrera

Zhaodong Chu

Yu Han

Michael C. Downer

Hailin Peng

Keji Lai

Abstract

Piezoelectric and ferroelectric properties in the two-dimensional (2D) limit are highly desired for nanoelectronic, electromechanical, and optoelectronic applications. Here we report the first experimental evidence of out-of-plane piezoelectricity and ferroelectricity in van der Waals layered α-In2Se3 nanoflakes. The noncentrosymmetric R3m symmetry of the α-In2Se3 samples is confirmed by scanning transmission electron microscopy, second-harmonic generation, and Raman spectroscopy measurements. Domains with opposite polarizations are visualized by piezo-response force microscopy. Single-point poling experiments suggest that the polarization is potentially switchable for α-In2Se3 nanoflakes with thicknesses down to ∼10 nm. The piezotronic effect is demonstrated in two-terminal devices, where the Schottky barrier can be modulated by the strain-induced piezopotential. Our work on polar α-In2Se3, one of the model 2D piezoelectrics and ferroelectrics with simple crystal structures, shows its great potential in electronic and photonic applications.

Citation

Zhou, Y., Wu, D., Zhu, Y., Cho, Y., He, Q., Yang, X., …Lai, K. (2017). Out-of-Plane Piezoelectricity and Ferroelectricity in Layered α-In2Se3 Nanoflakes. Nano Letters, 17(9), 5508-5513. https://doi.org/10.1021/acs.nanolett.7b02198

Journal Article Type	Article
Acceptance Date	Aug 24, 2017
Online Publication Date	Aug 25, 2017
Publication Date	Aug 25, 2017
Deposit Date	Oct 11, 2017
Publicly Available Date	Aug 25, 2018
Journal	Nano Letters
Print ISSN	1530-6984
Electronic ISSN	1530-6992
Publisher	American Chemical Society
Peer Reviewed	Peer Reviewed
Volume	17
Issue	9
Pages	5508-5513
DOI	https://doi.org/10.1021/acs.nanolett.7b02198

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Copyright Statement
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.nanolett.7b02198