摘要
近年来有一系列二维范德瓦耳斯材料铁电性被实验证实,层间滑移铁电体是其中重要的一类,该机制是传统铁电所没有,而很多二维材料普遍具有的.本文回顾了相关研究,介绍了这种铁电的起源:不少二维材料双层中上下两层并不对等,造成净层间垂直电荷转移,而层间滑移使该垂直铁电极化得以翻转.这种独特的滑移铁电可广泛存在于范德瓦耳斯双层、多层乃至体相结构中,层间滑移势垒较传统铁电低几个数量级,有望极大节约铁电翻转所需的能量.目前这种滑移铁电机制已在WTe_2和b-InSe双层/多层体系得到实验证实,不少预期极化更高的滑移铁电体系(如BN)也有望在近期实现.
In recent years,the existence of ferroelectricity in a series of two-dimensional van der Waals materials has been experimentally confirmed,in which the ferroelectricity induced by interlayer sliding is an important type.This mechanism is not available in traditional ferroelectrics but can be applied to many two-dimensional materials.In this paper we review the relevant researches and introduce the origin of this type of ferroelectricity:in many two-dimensional van der Waals bilayers,the upper layer is not equivalent to the lower layer,thus giving rise to a net interlayer charge transfer and the inducing vertical polarization to be switchable via interlayer sliding.This unique sliding ferroelectricity can widely exist in many van der Waals bilayers,multilayers and even bulk structures.The interlayer sliding barrier is several orders of magnitude lower than that of traditional ferroelectric,which may greatly save the energy required by ferroelectric switching.At present,this type of interlayer sliding ferroelectricity has been experimentally confirmed in WTe2 and b-InSe bilayer/multilayer systems,and more systems predicted to be with much stronger interlayer sliding ferroelectricity(like BN)may be realized in near future.
作者
钟婷婷
吴梦昊
Zhong Ting-Ting;Wu Meng-Hao(Department of Physics,Zhejiang Sci-Tech University,Hangzhou 310018,China;School of Physics,Huazhong University of Science and Technology,Wuhan 430074,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2020年第21期272-280,共9页
Acta Physica Sinica
关键词
二维范德瓦耳斯铁电体
层间滑移
纳米发电机
铁电莫列超晶格
two-dimensional van der Waals ferroelectrics
interlayer sliding
nanogenerator
ferroelectric Moire superlattice
