摘要
过渡金属Mn^(2+)掺杂的半导体/绝缘体作为发光材料在照明、显示等领域具有重要应用。Mn^(2+)离子具有5个未成对的d电子,掺杂在发光材料中通常具有高自旋态,其容易与近邻的Mn^(2+)离子发生交换或超交换作用即磁相互作用。此类相互作用可在分子尺度下对电子自旋产生很强的束缚能力,使得磁耦合Mn^(2+)-Mn^(2+)离子对的发光行为不同于孤立Mn^(2+)离子的发光行为,如荧光寿命变短、异常的发射波长红移/蓝移、多峰发射以及异常的磁光现象等。但由于受到浓度猝灭、缺陷、声子耦合、能量传递、与半导体激子的sp-d交换作用等多因素的影响以及测试技术的限制,对Mn^(2+)-Mn^(2+)离子间磁相互作用的确认及其对发光行为的影响仍存在较多争议。随着研究的不断深入和一些新的表征手段如光磁测量技术的引入,上述问题可以得到部分解决。本文首先简要介绍过渡金属离子磁相互作用类型及其理论基础;然后综述Mn^(2+)-Mn^(2+)离子间磁相互作用对其吸收光谱、发射光谱、荧光寿命和磁光效应的影响,并着重比较探讨了能证明Mn^(2+)-Mn^(2+)磁相互作用的存在及其作用类型的不同技术手段;最后进行总结并对此类材料在LED器件等领域的潜在应用进行了展望。
Transition metal ion Mn^(2+) doped semiconductors/insulators as luminescent materials have found significant applications in the fields of light-emitting diodes and displays.Due to the five unpaired electrons of Mn^(2+) and normally the high-spin state when used as dopants in luminescent materials,the exchange or superexchange interaction,i.e.,magnetic interaction,should easily take place between Mn^(2+)ion and the nearest neighbor Mn^(2+) ion.The interaction can generate a strong binding force at the molecular scale to the spin of electrons,making the luminescent behaviors of Mn^(2+)-Mn^(2+) pair different from that of isolate Mn^(2+),like the shortened decay lifetime,abnormal redshift/blueshift of the emissions,multi-band emissions and unusual magneto-optic behavior.However,the confirmation and assignment of magnetic interaction in Mn^(2+)-Mn^(2+)pair and its effect on luminescence behavior is still controversial because of the interference effects of concentration quenching,defect,phonon coupling,energy transfer,the sp-d exchange coupling between Mn^(2+)ions and exciton and the limitation of testing instruments.With the deepening of research and the introduction of some new techniques(like the photomagnetism measurement),the above issues can be partly solved.This review firstly introduces the fundamental theory and knowledge of magnetic interaction between transition metal ions.Then the effects of magnetic interaction of Mn^(2+)-Mn^(2+)pair on the absorption spectra,emission spectra,decay lifetime,and magneto-optical effect are reviewed.The virous measurement methods were emphatically compared and discussed to prove the existance of magnetic interaction in Mn^(2+)-Mn^(2+)and assign the type of interation.Finally,summary and some outlooks are given,concerning the potential applications of such materials in the field of LEDs devices.
作者
朱兴路
宋恩海
邹炳锁
叶柿
ZHU Xing-lu;SONG En-hai;ZOU Bing-suo;YE Shi(State Key Laboratory of Luminescent Materials and Devices and Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China;Guangxi Key Lab of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environments and Materials, Guangxi University, Nanning 530004, China)
出处
《发光学报》
EI
CAS
CSCD
北大核心
2022年第4期482-500,共19页
Chinese Journal of Luminescence
基金
国家自然科学基金(51772104)资助项目。
关键词
Mn^(2+)
磁相互作用
发光
Mn^(2+)
magnetic coupling interaction
luminescence
