稀土离子在KMnF_(3)纳米晶复合玻璃中的微观分布机理  

Mechanisms of rare earth ion distribution in fluorosilicate glass containing KMnF_(3) nanocrystal

作　　者：李文豪 谢玉清 石海征 芦鹏飞 任晶[1] Li Wen-Hao;Xie Yu-Qing;Shi Hai-Zheng;Lu Peng-Fei;Ren Jing(College of Physics and Optoelectronics Engineering,Harbin Engineering University,Harbin 150001,China;School of Optoelectronic Information,Beijing University of Posts and Telecommunications,Beijing 100876,China)

机构地区：[1]哈尔滨工程大学物理与光电工程学院,哈尔滨150001 [2]北京邮电大学光电信息学院,北京100876

出　　处：《物理学报》2022年第8期148-155,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51872055);中央高校基本科研业务费专项(批准号:3072020CF2515);高等学校学科创新引智计划(批准号:B13015)资助的课题~~。

摘　　要：具有单(纯)色上转换荧光发射特性的发光材料,有望在三维显示、照明、生物成像、促进植物生长以及提高太阳能电池光电转换效率等领域得到应用,受到研究人员的广泛关注.本研究通过玻璃热处理析晶的方法,在稀土离子Yb^(3+)/Er^(3+)共掺的氟硅酸盐玻璃中原位生长出了钙钛矿型的KMnF_(3)氟化物纳米晶体,并观测到了显著增强的高单色性上转换红色发光.采用具有高分辨率的透射电子显微测试分析技术和第一性原理计算相结合,研究了稀土离子在KMnF_(3)纳米晶复合微晶玻璃中的掺杂机制,并讨论了稀土离子微观分布和能量传递效应对其上转换发光性能的影响.实验结果表明:稀土离子将通过优先取代KMnF_(3)晶体中K^(+)格位的方式选择性富集在具有低声子能量的氟化物纳米晶体中,并由此获得显著增强的上转换发光强度.Luminescent materials with an efficient single-(pure)color up-conversion luminescence(UCL)are expected to be applied to three-dimensional(3D)display,lighting,biological imaging,promoting plant growth and improving the photoelectric conversion efficiency of solar cells.In this work,perovskite-type KMnF_(3) fluoride nanocrystals(NCs)are grown in situ in a fluorosilicate glass co-doped with rare earth(RE)ions Yb^(3+)/Er^(3+)by a controlled thermal treatment.Compared with precursor glass(PG),the nano-glass composites(also referred to as glass ceramics,or GC in short)thus obtained exhibit a significantly enhanced(by 6 times)red UCL emission.Although a weak green UCL emission can be also observed in the GC,the intensity ratio of the red UCL emission to green UCL emission is as high as 30,implying a good color purity.It is suggested that the dramatic enhancement of UCL emissions in the GCs is due to the doping of RE ions into the KMnF3 NCs with a much lower phonon energy(330 cm^(-1))than that of the silica glass matrix about 1100 cm^(-1).However,the doping mechanisms of RE ions into KMnF3 nano-glass composites are not yet conclusive,mainly because of the charge and ionic radius mismatch between RE ion dopants and cations of KMnF3.This work combines the high-resolution transmission electron microscopy(HR-TEM)analysis technology and the first principles calculation,to unravel the doping mechanism of RE ions in KMnF_(3) nano-glass composites.First,the HR-TEM study provides straightforward evidence that RE ions are preferentially accumulated in KMnF_(3) NCs embedded in the glass matrix.Then,through the first-principles calculation considering the charge balance,it is found that the formation energy of RE ions substituting for K^(+)is lower than for Mn^(2+) lattice sites in KMnF_(3),which is most likely related to the fact that the ionic radius of the eight-fold coordinated K+is larger than that of the six-fold coordinated Mn^(2+) and thus is more conductive to accommodating the large size RE ions.The electronic densities of

关 键 词：微晶玻璃 上转换发光 稀土离子掺杂 第一性原理计算 

分 类 号：TQ171.1[化学工程—玻璃工业] O482.31[化学工程—硅酸盐工业]