Pr3+∶Y2SiO5晶体中橙—蓝频率上转换过程

测量了Pr³⁺∶Y₂SiO₅晶体的吸收谱, 标定了室温下Pr³⁺在Y₂SiO₅晶体4f²组态内的能级. 利用579 nm激光激发Pr³⁺∶Y₂SiO₅晶体, 观察到480~515 nm上转换荧光带. 运用时间分辨激光光谱技术测量了³P₀能级的上转换荧光衰减曲线. 通过研究上转换荧光的衰减曲线、 吸收谱、 激发谱和上转换荧光强度与泵浦激光单脉冲能量的关系, 确定了以¹D₂为中间态的能量转移上转换主要是上转换机制.      

一种Er3+/Yb3+共掺锗碲铋钾玻璃的光谱性质

用熔融法制备了Er3 /Yb3 共掺TeO2-GeO2-B i2O3-K2O玻璃样品,对玻璃进行了差热分析并测试了玻璃的吸收光谱和上转换光谱.应用Judd-Ofelt理论计算了Er3 /Yb3 共掺锗碲铋钾玻璃的3个强度参数,及Er3 各能级的振子强度、自发辐射跃迁几率、荧光分支比和辐射寿命等光谱参数.通过977 nm的激光二极管抽运,在室温下同时观察到绿色(522和546 nm)和红色(658 nm)的荧光发射,分别是由于Er3 自2H11/2→4I15/24、S3/2→4I15/2和4F9/2→4I15/2跃迁而产生.强烈的绿光和红光发射均来源于双光子吸收过程.     

一种掺铒离子化合物的上转换发光的研究

合成了一种新型掺Er 离子化合物的上转换发光材料,测量了此材料在短波段的上转换发光光谱和激发光谱,初步研究了它们在短波段的上转换发光过程:短波段的上转换发光分别为三光子或四光子过程.还比较了掺杂敏化剂和不掺敏化剂两种情况下的上转换发光的变化情况     

稀土掺杂的光谱转换材料及其应用

以LED红色荧光粉材料、近红外下转换材料和上转换生物荧光标记材料为主线,结合我们实验室近期具体的相关研究工作,对稀土掺杂的光谱转换材料及其潜在的应用前景进行了简要介绍.在LED红色荧光粉材料方面,以Eu3＋掺杂的红色荧光材料为对象,研究通过基质或掺杂敏化剂到Eu3＋的能量传递来提高材料在近紫外波段的激发效率,并且在Y2MoO6材料中通过基质的电荷迁移带到Eu3＋的能量传递在395nm的近紫外激发条件下获得了2.3倍于商用LED荧光粉（Y2O2S：Eu3＋）的发光强度.在近红外下转换材料方面,分别研究了通过从其他稀土离子到Yb3＋的逐次能量传递和从基质到Yb3＋的合作能量传递实现近红外下转换,主要介绍了两种典型材料中的能量传递机理,氟化物中Ho3＋到Yb3＋的逐次能量传递和YVO4中VO43-到Yb3＋的合作能量传递.在上转换生物荧光标记材料方面,利用以油酸/十八烯为溶剂的湿化学法合成了单分散、粒径在20nm左右、具有核/壳结构和水溶性的球形NaYF4：Yb3＋,Er3＋（Tm3＋）纳米粒子,并对其在不同环境中的稳定性和在细胞中的荧光成像性质做了研究,在此基础上还对下一步可能的深化研究进行了探讨.不断拓展的研究方向和层出不穷的研究结果表明稀土掺杂的光谱转换材料是新型功能材料的重要研究领域,目前和将来在生物和化学传感、节能环保和新能源等领域有着重要的应用或应用前景,需要深入研究.     

Effect of alkali metal oxides on upconversion fluorescence properties of germanatetellurite glasses

Upconversion emissions of Yb^3 /Er^3 -codoped germanate-tellurite glasses have been investigated upon the excitation of 980 nm laser diode (LD). It is found that upconversion luminescence intensities significantly increase with the increasing size of alkali metal ions. Raman spectra show that the maximum phonon energies (MPE) of glass hosts are unchanged with the replacement of alkali metal oxides, indicating that MPE is not the reason for the increase of upconversion fluorescence intensities. The analysis of the non-radiative transition of Er^3 demonstrates that the decrease of the maximum energy phonon density is the main reason for the enhanced fluorescence intensities.     

稀土Er3+/Yb3+/Ho3+掺杂能量上转换发光研究进展

介绍了基质材料的最新研究进展,以单掺或共掺的Er3 ,Yb3 ,Ho3 离子为例,详细的阐述了稀土离子的多种上转换机制,最后提出了今后的研究方向.     

稀土铒离子掺杂的ZrF2-SiO2发光性质研究

制备了Er3+掺杂的ZrF2-SiO2材料,测量样品的吸收谱和在980nmLD激发下的上转换荧光发射谱.分析了稀土Er3+中4f电子跃迁的特征,证实了在980nm泵浦的激发下,ZrF2-SiO2Er3+在404、445nm和525、548nm附近的蓝/绿可见波段上转换发光过程是激发态吸收(ESA).     

Growth, structure and upconversion mechanisms of Ba2ErCl7 crystal

The methods to grow a novel upconversion crystal Ba2ErCl7 are reported in this note. Ba2ErCl7 material was synthesized with Er2O3, BaCl2.2H2O and NH4Cl by using a so-called "direct synthesis method". High quality Ba2ErCl7 single crystals with size up to 4 mm×8 mm×15 mm were grown by using the Czochralski and the Bridgman methods. Intense yellow-green luminescence was detected when the crystal was pumped by an 803 laser diode (LD). Transmittance spectrum was measured by using HITACH U-3500 spectrophotometer at room temperature for the first time, in which one can see that the transmittance is high in the range from 350 to 1 600 nm and the cut-off wavelength of the crystal was 230 nm. The upconversion mechanisms were discussed.     

Preparation and luminescence properties of YeO3：Er^3＋/TiO2 with high specific surface area

The three composites Y2O3 :Er3+ , Y2O3 :Er3+ /Yb 3+ andY2O3 :Er3+ /TiO2 were prepared using coprecipitation and sol-gel techniques. Their morphology, specific surface area, porosity, UV-vis. absorption spectra and fluorescence spectra were measured using SEM, TEM, surface analysis, UV-vis. absorption and photoluminescence spectrophotometry. SEM and TEM showed that samples prepared using coprecipitation were dispersed, while Y2O3 :Er3+ /TiO2 particles possessed a mesoporous surface and average diameter of ab...     

上转换发光纳米材料在生物成像中应用的研究进展

稀土上转换发光纳米材料是一类利用近红外光激发而短波长发射的荧光材料, 因其具有发光性质稳定、无光漂白现象、弱的生物样品损伤和高荧光信噪比等优点, 在荧光成像中可弥补传统荧光标记材料的不足而发挥重要作用. 本文重点介绍上转换发光纳米材料在生物成像中应用的进展.