Supertetragonal BaZrS_(3):A promising perovskite sulphide with giant ferroelectricity and low band gap  

作　　者：Menglu Li Sa Zhang Chenhan Liu Xiaotao Zu Liang Qiao Haiyan Xiao 

机构地区：[1]School of Physics,University of Electronic Science and Technology of China,Chengdu 611731,China [2]College of Mathematics and Physics,Chengdu University of Technology,Chengdu 610059,China [3]Micro-and Nano-scale Thermal Measurement and Thermal Management Laboratory,Ministry of Education Key Laboratory of Numerical Simulation of Large-Scale Complex Systems,School of Energy and Mechanical Engineering,Nanjing Normal University,Nanjing 210023,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2024年第8期126-133,共8页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.52072059,and 11774044);supported by the Joint Funds of the National Natural Science Foundation of China(Grant No.U1930120)。

摘　　要：Over the past century,ferroelectricity has offered exciting opportunities for fundamental research and device applications.However,most of the discovered excellent ferroelectrics are oxide materials with large band gaps,limiting their potential for optoelectronics applications.Here using first-principles calculations we identify a new narrow-gap ferroelectric beyond oxides,i.e.,ferroelectric perovskite sulphide BaZrS_(3).Under large compressive strains,BaZrS_(3)can be stabilized into a unique supertetragonal phase with an extraordinary polarization of 67.16μC/cm^(2),which is even stronger than that of conventional oxide ferroelectrics.Excitingly,the supertetragonal BaZrS_(3)exhibits a direct narrow band gap of 1.2 eV and excellent electronic properties.Based on the chemical bonding analysis,we attribute the formation of supertetragonal phase to charge re-ordering in which theπbond overlap along the long〈Zr-S〉bond completely vanishes and the antibonding states of theσbond appear below the Fermi level.Our work provides a conceptual strategy for designing new ferroelectrics for electronic and photovoltaic applications.

关 键 词：supertetragonal phase perovskite sulphide FERROELECTRICITY 

分 类 号：O469[理学—凝聚态物理]