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Room‐Temperature Ferroelectricity in Hexagonally Layered α‐In 2 Se 3 Nanoflakes down to the Monolayer Limit
Author(s) -
Xue Fei,
Hu Weijin,
Lee KoChun,
Lu LiSyuan,
Zhang Junwei,
Tang HaoLing,
Han Ali,
Hsu WeiTing,
Tu Shaobo,
Chang WenHao,
Lien ChenHsin,
He JrHau,
Zhang Zhidong,
Li LainJong,
Zhang Xixiang
Publication year - 2018
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201803738
Subject(s) - ferroelectricity , materials science , monolayer , van der waals force , condensed matter physics , heterojunction , stacking , polarization (electrochemistry) , electric field , nanotechnology , hysteresis , optoelectronics , nuclear magnetic resonance , chemistry , dielectric , molecule , physics , quantum mechanics
Abstract 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‐In 2 Se 3 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‐In 2 Se 3 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‐In 2 Se 3 are developed, which are applicable for nonvolatile memories and heterostructure‐based nanoelectronics/optoelectronics.