Out-of-plane and in-plane ferroelectricity of atom-thick two-dimensional InSe

Haowen Hu; Huaipeng Wang; Yilin Sun; Jiawei Li; Jinliang Wei; Dan Xie; Hongwei Zhu

doi:10.1088/1361-6528/ac0ac5

Out-of-plane and in-plane ferroelectricity of atom-thick two-dimensional InSe

Nanotechnology. 2021 Jun 29;32(38). doi: 10.1088/1361-6528/ac0ac5.

Authors

Haowen Hu¹, Huaipeng Wang², Yilin Sun^{2

3}, Jiawei Li¹, Jinliang Wei², Dan Xie², Hongwei Zhu¹

Affiliations

¹ State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China.
² Beijing National Research Center for Information Science and Technology (BNRist), Institute of Microelectronics, Tsinghua University, Beijing 100084, People's Republic of China.
³ School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, People's Republic of China.

PMID: 34116515
DOI: 10.1088/1361-6528/ac0ac5

Abstract

Two-dimensional (2D) ferroelectric materials are promising substitutes of three-dimensional perovskite based ferroelectric ceramic materials. Yet most studies have been focused on the construction of non-centrosymmetric 2D van der Waals materials and only a few are constructed experimentally. Herein, we experimentally demonstrate the co-existence of voltage-tunable out-of-plane (OOP) and in-plane (IP) ferroelectricity in few-layer InSe prepared by a solution-processable method and fabricate ferroelectric semiconductor channel transistors. The reversible polarization can initiate instant switch of resistance with high ON/OFF ratios and a comparable subthreshold swing of 160 mV/dec under gate modulation. The origins of such unique OOP and IP ferroelectricity of the centrosymmetric structure are theoretically analyzed.

Keywords: InSe; ferroelectricity; subthreshold swing; two-dimensional materials.