Multidirection Piezoelectricity in Mono- and Multilayered Hexagonal α-In2Se3

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Fei Xue
  • Junwei Zhang
  • Weijin Hu
  • Wei-Ting Hsu
  • Ali Han
  • Siu-Fung Leung
  • Jing-Kai Huang
  • Yi Wan
  • Shuhai Liu
  • Junli Zhang
  • Wen-Hao Chang
  • Zhong Lin Wang
  • Xixiang Zhang
  • Lain-Jong Li

Detail(s)

Original languageEnglish
Pages (from-to)4976-4983
Journal / PublicationACS Nano
Volume12
Issue number5
Online published25 Apr 2018
Publication statusPublished - 22 May 2018
Externally publishedYes

Abstract

Piezoelectric materials have been widely used for sensors, actuators, electronics, and energy conversion. Two-dimensional (2D) ultrathin semiconductors, such as monolayer h-BN and MoS2 with their atom-level geometry, are currently emerging as new and attractive members of the piezoelectric family. However, their piezoelectric polarization is commonly limited to the in-plane direction of odd-number ultrathin layers, largely restricting their application in integrated nanoelectromechanical systems. Recently, theoretical calculations have predicted the existence of out-of-plane and in-plane piezoelectricity in monolayer α-In2Se3. Here, we experimentally report the coexistence of out-of-plane and in-plane piezoelectricity in monolayer to bulk α-In2Se3, attributed to their noncentrosymmetry originating from the hexagonal stacking. Specifically, the corresponding d33 piezoelectric coefficient of α-In2Se3 increases from 0.34 pm/V (monolayer) to 5.6 pm/V (bulk) without any odd-even effect. In addition, we also demonstrate a type of α-In2Se3-based flexible piezoelectric nanogenerator as an energy-harvesting cell and electronic skin. The out-of-plane and in-plane piezoelectricity in α-In2Se3 flakes offers an opportunity to enable both directional and nondirectional piezoelectric devices to be applicable for self-powered systems and adaptive and strain-tunable electronics/optoelectronics.

Research Area(s)

  • monolayer and bulk, multidirection, nanogenerator and electronic skin, piezoelectricity, van der Waals crystal

Citation Format(s)

Multidirection Piezoelectricity in Mono- and Multilayered Hexagonal α-In2Se3. / Xue, Fei; Zhang, Junwei; Hu, Weijin et al.

In: ACS Nano, Vol. 12, No. 5, 22.05.2018, p. 4976-4983.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review