CH3NH3PbBr3纳米线中束缚激子g因子的各向异性  

The g-factor anisotropy of trapped excitons in CH3NH3PbBr3 perovskite

作　　者：宋飞龙 王玉暖 张峰 武诗谣 谢昕[1,2] 杨静南 孙思白 党剑臣 肖姗 杨龙龙 钟海政 许秀来[1,2,5] Song Fei-Long;Wang Yu-Nuan;Zhang Feng;Wu Shi-Yao;Xie Xin;Yang Jing-Nan;Sun Si-Bai;Dang Jian-Chen;Xiao Shan;Yang Long-Long;Zhong Hai-Zheng;Xu Xiu-Lai(Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;School of Science,Beijing Jiaotong University,Beijing 100044,China;School of Materials Science&Engineering,Beijing Institute of Technology,Beijing 100081,China;Songshan Lake Materials Laboratory,Dongguan 523808,China)

机构地区：[1]中国科学院物理研究所,北京凝聚态物理国家研究中心,北京100190 [2]中国科学院大学物理学院,中国科学院拓扑量子计算卓越创新中心,北京100049 [3]北京交通大学理学院,北京100044 [4]北京理工大学材料学院,北京100081 [5]松山湖材料实验室,东莞523808

出　　处：《物理学报》2020年第16期202-209,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11934019,61675228,11721404,51761145104,11874419);中国科学院先导项目(批准号:XDB28000000);中国科学院仪器研制项目(批准号:YJKYYQ20180036);中国科学院创新交叉团队项目;广东省重点研发计划(批准号:2018B030329001)资助的课题

摘　　要：有机-无机杂化钙钛矿材料与其他半导体材料相比具有高的缺陷容忍率,在太阳能电池、发光二极管、低阈值激光器等领域有重要的应用前景.通常情况下,钙钛矿材料是通过溶液法合成的,这种方法虽然可以得到性能优异的钙钛矿器件,但同时也会在合成过程中产生大量缺陷.尽管目前在理论和实验上对钙钛矿材料的缺陷做了很多研究,但对单个缺陷附近的束缚激子发光问题的研究较少.本文通过共聚焦显微系统研究了低温(4.2 K)下单根钙钛矿纳米线的荧光光谱,观测到来自于缺陷周围束缚激子的窄线宽和高强度的荧光峰,同时观测到了磁场下的塞曼分裂和抗磁现象,并通过施加矢量磁场发现了束缚激子的g因子存在各向异性.单个束缚态激子的磁光性质的研究为深入理解束缚激子在量子光源以及自旋电子学中的应用提供了依据.Hybrid organic-inorganic perovskites show large potential applications in solar cells,light emitting diodes and low threshold lasers because of the high tolerance of defects compared with other semiconductor materials.Normally they have been synthesized by dilution method,generating a device with high performance,but they also introduce lots of defects.So far,investigations have been done intensively on ensemble defects both in theory and experiment,but single-defect related trapped excitons are yet to be explored.In this work,we prepared high-quality CH3NH3PbBr3 perovskite nanowires with the length of about 1μm and the width of several hundred nanometers by“reverse”ligand assisted reprecipitation method,and performed the magnetophotoluminescence measurement of different trapped excitons in single perovskite nanowires at a low temperature with a standard confocal microscopic system.The photoluminescence(PL)peak with narrow linewidth has been observed from trapped excitons with high luminescence intensity and the trapped excitons can be coupled with phonons in different ways.Both Zeeman splittings and diamagnetic effects have been observed in single trapped excitons under the magnetic field,and we found that the different trapped excitons have different Zeeman splittings and diamagnetic effects which is caused by the different defects near the trapped excitons.At the same time,we have extracted the g-factor of the trapped excitons under different magnetic field angles.The extracted exciton g-factors show anisotropic,which can be ascribed to the limitation of the lattice structure of the perovskite and the trapped exciton wave-function anisotropy under a vector magnetic field.Our results demonstrate that trapped excitons with narrow linewidth have very good luminescence properties and studying the magneto-optical properties from single trapped excitons can provide a deep understanding of trapped excitons in perovskites for applications in quantum light sources and spintronics.Furthermore,our results can also p

关 键 词：钙钛矿纳米线 磁光光谱 g 因子各向异性 抗磁效应 

分 类 号：O469[理学—凝聚态物理]