Room-Temperature Ferroelectricity in Hexagonally Layered α-In2\nSe3\n Nanoflakes down to the Monolayer Limit

Fei Xue, Weijin Hu, Ko-Chun Lee, Li-Syuan Lu, Junwei Zhang, Hao-Ling Tang, Ali Han, Wei-Ting Hsu, Shao Bo Tu, Wen-Hao Chang, Chen-Hsin Lien, Jr-Hau He, Zhidong Zhang, Lain-Jong Li, Xixiang Zhang

Research output: Contribution to journalArticlepeer-review

170 Scopus citations


2D ferroelectric material has emerged as an attractive building block for high-density data storage nanodevices. Although monolayer van der Waals ferroelectrics have been theoretically predicted, a key experimental breakthrough for such calculations is still not realized. Here, hexagonally stacking α-InSe nanoflake, a rarely studied van der Waals polymorph, is reported to exhibit out-of-plane (OOP) and in-plane (IP) ferroelectricity at room temperature. Ferroelectric multidomain states in a hexagonal α-InSe nanoflake with uniform thickness can survive to 6 nm. Most strikingly, the electric-field-induced polarization switching and hysteresis loop are, respectively, observed down to the bilayer and monolayer (≈1.2 nm) thicknesses, which designates it as the thinnest layered ferroelectric and verifies the corresponding theoretical calculation. In addition, two types of ferroelectric nanodevices employing the OOP and IP polarizations in 2H α-InSe are developed, which are applicable for nonvolatile memories and heterostructure-based nanoelectronics/optoelectronics.
Original languageEnglish (US)
Pages (from-to)1803738
JournalAdvanced Functional Materials
Issue number50
StatePublished - Oct 21 2018

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): CRF-2015-2634-CRG4, CRF-2016-2996-CRG5
Acknowledgements: F.X., W.H., and K.-C.L. contributed equally to this work. The research presented here was supported by King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award No: CRF-2015-2634-CRG4, and CRF-2016-2996-CRG5. W.J.H thanks the support from the “Hundred Talents Program” of the Chinese Academy of Sciences. W.-H.C. acknowledges the support from the Ministry of Science and Technology (MOST) of Taiwan (105-2119-M-009-014-MY3, 107-2112-M-009-024-MY3) and the Center for Emergent Functional Matter Science (CEFMS) of NCTU.


Dive into the research topics of 'Room-Temperature Ferroelectricity in Hexagonally Layered α-In2\nSe3\n Nanoflakes down to the Monolayer Limit'. Together they form a unique fingerprint.

Cite this