Enhanced domain wall conductivity in photosensitive ferroelectrics Sn_(2)P_(2)S_(6) with full-visible-spectrum absorption  

全可见光吸收的光敏铁电材料Sn_(2)P_(2)S_(6)具有增强的畴壁导电性

作　　者：Jianming Deng Xing’an Jiang Yanyu Liu Wei Zhao Gang Tang Yun Li Sheng Xu Jinchen Wang Cheng Zhu Meixia Wu Jing Wang Zishuo Yao Qi Chen Xiaolei Wang Tian-Long Xia Xueyun Wang Jiawang Hong 邓建明;江兴安;刘彦昱;赵威;唐刚;李昀;徐升;汪晋辰;朱城;吴枚霞;王静;姚子硕;陈棋;王晓蕾;夏天龙;王学云;洪家旺(School of Aerospace Engineering,Beijing Institute of Technology,Beijing,100081,China;School of Chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing,100081,China;Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano Devices,Renmin University of China,Beijing,100872,China;Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems,School of Materials Science&Engineering,Beijing Institute of Technology,Beijing,100081,China;Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education,School of Chemistry,Sun Yat-Sen University,Guangzhou,510275,China;Advanced Research Institute of Multidisciplinary Science,Beijing Institute of Technology,Beijing,100081,China;College of Physics and Optoelectronics,Faculty of Science,Beijing University of Technology,Beijing,100124,China)

机构地区：[1]School of Aerospace Engineering,Beijing Institute of Technology,Beijing,100081,China [2]School of Chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing,100081,China [3]Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano Devices,Renmin University of China,Beijing,100872,China [4]Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems,School of Materials Science&Engineering,Beijing Institute of Technology,Beijing,100081,China [5]Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education,School of Chemistry,Sun Yat-Sen University,Guangzhou,510275,China [6]Advanced Research Institute of Multidisciplinary Science,Beijing Institute of Technology,Beijing,100081,China [7]College of Physics and Optoelectronics,Faculty of Science,Beijing University of Technology,Beijing,100124,China

出　　处：《Science China Materials》2022年第4期1049-1056,共8页中国科学（材料科学（英文版）

基　　金：supported by the National Key Research and Development Program of China(2019YFA0307900);the National Natural Science Foundation of China(12172047,92163101,11804023);Beijing Natural Science Foundation(Z190011);China Postdoctoral Science Foundation(2018M641205)。

摘　　要：Recent optical stimulation suggests a vital non-contact pathway to manipulate both macroscopic and microscopic ferroelectric properties and paves the foundation for optoelectronics devices.However,up to date,most optical-related manipulation of ferroelectric properties is restricted due to their intrinsic bandgap and limited visible light spectrum absorption.Here,we reveal non-oxide Sn_(2)P_(2)S_(6) single crystal possesses full-visible-spectrum absorption(from 300 to 800 nm)with a unique disproportionation mechanism of photoexcited Sn ions and Urbach tail,which is not contradicting to the intrinsic band gap.Interestingly,we observed the existence of conductive domain walls(c-DW)and the light illumination induced significant enhancement of the domain wall conductivity caused by such disproportionation reaction.In addition,the domains separated by c-DW also exhibited noticeable electrical conductivity difference in the presence of optical illumination owing to the interfacial polarization charge with opposite signs.The result provides a novel opportunity for understanding the electrical conductivity behavior of the domains and domain walls in ferroelectrics with full-visible-spectrum absorption and achieving greatly enhanced performances for optoelectronics.近年来,光学调控成为一种重要的操纵宏观和微观铁电性能的非接触调控方式,为光电子器件的发展奠定了基础.然而,目前大多数功能铁电材料的光学调控都受到其本征带隙及有限的可见光吸收特性的限制.针对上述铁电材料中光学调控存在的限制,我们报道了一种全可见光吸收(300-800 nm)的非氧化物铁电单晶材料Sn_(2)P_(2)S_(6).结合缺陷分析和第一性原理计算方法揭示了光激发Sn离子的歧化反应和乌尔巴赫带尾增强可见光吸收的机制,这与Sn_(2)P_(2)S_(6)的本征带隙并不矛盾.有趣的是,我们在非氧化物铁电体中观测到导电的畴壁,而且歧化反应引起光致畴壁的导电性显著增强.此外,光照条件下相反取向的铁电畴展现出明显的导电性差异,这是由电畴表面的异号电荷引起界面能带弯曲所致.该工作为全可见光吸收铁电材料中的电畴和畴壁的导电行为以及改善光电子学性能提供了一个全新的思路.

关 键 词：Sn_(2)P_(2)S_(6) FERROELECTRICITY conductive domain walls full-visible-spectrum absorption 

分 类 号：TB34[一般工业技术—材料科学与工程]