单颗粒NaYF4核壳结构的能量传递特性  

Energy transfer characteristics of single-particle NaYF4 core-shell structure

作　　者：高伟 张晶晶 韩珊珊 邢宇 邵琳 陈斌辉 韩庆艳 严学文 张成云 董军 Gao Wei;Zhang Jing-Jing;Han Shan-Shan;Xing Yu;Shao Lin;Chen Bin-Hui;Han Qing-Yan;Yan Xue-Wen;Zhang Cheng-Yun;Dong Jun(School of Electronic Engineering,Xi’an University of Posts&Telecommunications,Xi’an 710121,China)

机构地区：[1]西安邮电大学电子工程学院,西安710121

出　　处：《物理学报》2022年第23期269-279,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12004304,12104366);陕西省重点研发项目(批准号:2022SF-333);陕西省青年科技新星项目(批准号:2021KJXX-45);陕西省自然科学基金重点项目(批准号:2022JZ-05);陕西省自然科学基金青年基金(批准号:2022JQ-041);西安邮电大学研究生创新基金(批准号:CXJJDL2021002)资助的课题.

摘　　要：基于晶体外延生长技术构建稀土掺杂的微纳米核壳结构,不仅有利于增强稀土离子的发射强度,且可通过对离子的空间分离实现其发光颜色的精细调控.为此,本工作巧妙地借助外延生长技术构建了一系列掺杂不同离子浓度的NaYF4@NaYF4核壳结构微米晶体.在980 nm近红外光激发下,借助共聚焦显微光谱测试系统,通过改变激发位置,研究了掺杂离子在单颗粒核壳微米晶体中的能量传递特性.研究表明,当改变其激发位置时,核壳微米盘不同区域掺杂的离子均展现出了不同的光谱特性,其原因主要是由于在核壳结构中激发能传递方向不同所致.基于其不同位置发射光谱及功率变化光谱,证实微米核壳的激发能量主要是由外向内传递.同时依据相应的光波导模型,揭示了核壳结构微米盘多彩发射图案的产生.由此可见,通过构建不同微米核壳结构,不仅能实现微米晶体发光特性的可控调节,而且为进一步拓展微米晶体在光电子器件、光学编码及多色显示等领域中的应用提供重要的实验参考.The rare-earth doped micro/nano core-shell structure not only is beneficial to enhancing the upconversion emission intensity,but also can realize the fine control of luminescence color through the spatial separation of ions.In this work,a series of NaYF4@NaYF4 core-shell(CS)microcrystals doped with different ion concentrations is constructed by using the epitaxial growth technology.The structure and morphology for each of the prepared microcrystals are characterized by X-ray diffractometer(XRD)and scanning electron microscope(SEM).The experimental results show that the prepared CS structures each have a pure hexagonal-phase crystal structure,and exhibit a disk-like shape.Under the excitation of 980 nm laser,the energy transfer characteristics of doped ions in single CS microcrystal are carefully studied by using a confocal microscope spectroscopy test system and changing the excitation position.The study shows that the ions doped in different regions of the CS microdisks exhibit different spectral characteristics when the excitation position is changed,which is mainly due to the different directions of excitation energy transfer in the CS structure.Based on the emission spectra of different positions and power variation spectra,it is proved that the excitation energy of the micron CS is mainly transmitted from outside to inside.Meanwhile,the colorful emission pattern of the CS microdisk is revealed by the corresponding optical waveguide model,which is mainly due to the optical waveguide effect.Therefore,by constructing different micron core-shell structures,the luminescence characteristics of microcrystals can be controlled and adjusted,which can provide important experimental reference for the applications of microcrystals in optoelectronic devices,optical coding and multicolor display.

关 键 词：单颗粒 微米核壳结构 上转换发光调控 能量传递 光波导效应 

分 类 号：TB34[一般工业技术—材料科学与工程] O782[理学—晶体学]