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

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
• Public URL: https://durham-repository.worktribe.com/output/1346738