芪3在铅-锡-氟磷酸盐玻璃中的聚集及光谱特性

采用低温熔融法制备了有机染料芪3掺杂的不同浓度的铅-锡-氟磷酸盐玻璃,通过对掺杂玻璃激发光谱、发射光谱和吸收光谱的测试,研究了芪3在无机玻璃中的聚集状态和光谱性能。 结果表明,有机染料芪3以单体和二聚物的形式共存于无机玻璃中,和芪3单体分子的激发峰相比,二聚物的激发峰位于短波段,随掺杂浓度的增加,掺杂玻璃的发射峰发生红移,同时在荧光光谱中观察到浓度猝灭现象;芪3分子与无机玻璃通过亲水作用发生了键合,从而导致芪3在无机玻璃中的吸收光谱和发射光谱比在乙醇溶液中出现较大红移;与芪3在乙醇溶液中的荧光强度相比,芪3分子受无机玻璃的“笼”化作用有效的提高了其荧光强度。     

硅烷偶联剂改性的芪3掺杂铅-锡-氟磷酸盐玻璃发光性能的研究

采用硅烷偶联剂KBM403对SnF2粉末进行表面改性,改性粉末的IR透射谱显示KBM403已经吸附在SnF2粉末表面,这种改性除了物理吸附外还存在微弱的化学吸附。采用溶有芪3的硅烷偶联剂KBM403对SnF2粉末进行改性,经改性的SnF2粉末有利于提高有机染料芪3掺杂的分散性。将含有芪3的改性SnF2粉末掺入低熔点铅-锡-氟磷酸盐玻璃,获得了芪3掺杂的有机/无机杂化玻璃。对玻璃的吸收、透射谱和激发发射谱进行分析,表明KBM403的介入改善了芪3在玻璃中的溶解性和分散性,减少了芪3二聚物的产生,提高了玻璃的透射率和均匀性。由于KBM403的改性减少了芪3二聚物所带来的荧光猝灭,同时KBM403与染料分子的相互作用增加了染料分子的刚性,玻璃的发光强度显著提高。     

高效氟磷酸盐玻璃白光荧光体制备及发光特性

采用熔融淬火方法制备了一系列Sn2+，Dy3+单掺及Sn2+-Dy3+共掺氟磷酸盐玻璃荧光体。利用紫外-可见分光光度计分别对各玻璃荧光体的透过光谱、激发光谱、发射光谱及荧光寿命等进行了测试和分析。结果发现在紫外光激发下，对于Sn2+、Dy3+单掺氟磷酸盐玻璃可分别获得高效的蓝光与黄光发射，且Sn2+单掺氟磷酸盐玻璃荧光体发光显色指数和量子效率最高；对于Sn2+-Dy3+共掺氟磷酸盐玻璃荧光体可实现高效的白光发射，且发现在Sn2+和Dy3+之间存在明显的能量传递，通过调节Dy3+掺杂浓度，两离子之间的能量转移效率亦随之改变，从而可对其白光色度进行调节。当Dy3+掺杂浓度为3 Wt%时，利用280 nm商用LED芯片激发可获得对应色坐标为(0.311，0.330)，量子效率为56.3%，亮度为6 706 cd·m-2的近纯白光发射。此外，对各类玻璃样品的DSC、导热及其他光学性能也进行了测试与计算，获得了各样品的热导率、量子效率、色坐标、显色指数等参数。研究结果表明，制备的高效氟磷酸盐玻璃完全有望作为可调谐白光发光荧光体应用于商用LED。     

氟磷酸盐光学玻璃(综述)

本文对具有优越的消二级光谱性能的氟磷酸盐光学玻璃的国内外发展概况作了综述。扼要地阐述了氟磷酸盐玻璃消二级光谱的重要特性,氟磷酸盐玻璃的结构及特殊色散机理,介绍并评价了氟磷酸盐玻璃的若干典型配方、新工艺,提出了展望意见。     

碱金属和碱土金属氟化物对掺Er3+氟磷酸盐玻璃光谱性质的影响

研究了碱金属和碱土金属离子修饰的掺Er3+氟磷酸盐玻璃的光谱性质,讨论了碱金属和碱土金属对铒氟磷玻璃的吸收和发射截面、荧光半高宽,Judd-Ofelt强度参数和上转换发光强度等光谱性质的影响,并与一些传统氧化物玻璃系统进行了比较.研究表明碱金属K+和碱土金属Sr2+掺杂高的玻璃更适宜用作光放大器基质.含12mol%K+的氟磷玻璃展现出7.83×10-21cm2的高发射截面和最小的荧光上转换强度;含23mol%Sr2+的氟磷玻璃则有7.58×10-21cm2的高发射截面、65nm的荧光半高宽及8.6ms的长的上能级荧光寿命.     

4-四氢喹啉酮的合成及发光性能

对喹吖啶酮结构改造合成了新型结构荧光体4-四氢喹啉酮,对其吸收光谱及荧光光谱进行了研究,发现该化合物的吸收峰及荧光发射峰随溶剂极性的增加而不断红移,表明荧光来源于分子内激发态电荷转移发光.该化合物在固态即显示荧光,表明经结构改造后,消除了喹吖啶酮类的固态荧光猝灭效应.4-四氢喹啉酮结构简单,易于合成和结构修饰.这对于寻找新的主体荧光发射材料具有重大意义.     

Er3+/Yb3+共掺的氟磷酸盐玻璃的光谱性质和热稳定性

研究了Er3+/Yb3+共掺的氟磷酸盐玻璃的光谱性质和热稳定性。应用Judd-Ofelt理论计算了玻璃的三个强度参量Ωｔ (ｔ=2,4,6)，计算了Er3+离子的辐射跃迁几率，荧光支效率和自发辐射几率等光谱参量。 经荧光谱测试发现掺Er3+/Yb3+共掺的氟磷酸盐玻璃的荧光半高宽可达63nm ，应用McCumber理论计算了1.53μｍ处的受激发射截面，可达6.85×10-21 cm2。     

掺杂有机染料的铅锡氟磷酸闪烁玻璃及其在伽马激发下的发光

制备了掺杂有机染料芪420的铅锡氟磷酸盐杂化闪烁玻璃(lead tin fluorophosphates,简记为PTFP),测量其玻璃转变温度为75℃,染料在玻璃中的荧光发射峰位为446nm.测量了几种掺杂浓度的闪烁玻璃在⁶⁰Co源1.25MeV伽马射线激发下的发光,并和同样厚度的有机闪烁体ST401的发光进行比较,约为ST401发光的1%—2%. 关键词： 铅锡氟磷酸 闪烁玻璃 芪420 伽马     

掺铜磷酸盐和氟磷酸盐玻璃的光谱研究

本文对掺铜Ca-Al磷酸盐玻璃和、Na-Mg-Ca-Sr-Ba-Al氟磷酸盐玻璃分别作了吸收光谱、ESR谱、激发光谱、荧光光谱和荧光寿命测定。实验结果表明,玻璃中的Cu2+在近红外有一吸收带,属于畸变0h格位中2Eg→2T2g的跃迁。Cu+在紫外区有一吸收带,属于3d10→3d94s1跃迁。用紫外激发,玻璃中Cu+在可见区有一较宽的发光带。磷酸盐玻璃中,荧光峰值位于458nm。氟磷酸盐玻璃中,荧光峰值位于420nm。前者荧光寿命为26μs,后者为60μs。     

溶胶凝胶介孔AlPO_4玻璃镶嵌香豆素102的光学性质

运用新型溶胶凝胶法制备了高比表面积介孔AlPO4玻璃,并通过浸渍法将香豆素102染料镶嵌入该玻璃中。利用激发光谱和荧光光谱方法研究了香豆素102染料镶嵌浓度对光学性质和染料分子的形态的影响。激发光谱结果表明,香豆素102单体分子在介孔AlPO4玻璃中的激发带主要在366 nm处。随着染料摩尔分数从5×10-6mol/L增加到5×10-3mol/L,激发峰分裂并逐渐增宽,说明染料分子在介孔玻璃中逐渐聚集成J-二聚体。荧光光谱结果显示,随着染料摩尔分数从5×10-6mol/L增加到5×10-3mol/L,主要荧光峰从459 nm红移到479 nm。在浓度5×10-3mol/L时,可调谐宽度达135 nm。浸析实验证明染料在介孔AlPO4玻璃中稳定性很好。     

掺Er凝胶玻璃中Er离子发光性质的研究

用溶胶－凝胶方法合成了掺铒的二氧化硅玻璃。在室温下可产生１．５４μｍ波长的红外荧光。实验结果表明：荧光强度随掺杂浓度的不同而改变，并在０．５Ｗ％的掺杂浓度下出现最大值。当温度从４Ｋ升至３００Ｋ时，荧光强度下降了７４％。     

The photoluminescent properties of Eu in MgO-Ga2O3-SiO2 nanocrystalline glass-ceramic

The MgO-Ga₂O₃-SiO₂ glass-ceramic (GC) containing MgGa₂O₄ nanocrystals and glasses doped with Eu³⁺ ions were prepared by the sol-gel method. The down-conversion and up-conversion luminescence (UCL) properties were studied. The results indicated that the relative intensity of f-f transitions of Eu³⁺ decreased in contrast with that of charge transfer (CT) absorption with the increase in heating temperature. Using a Xe lamp and 800 nm femtosecond (fs) laser excitation, strong red luminescence of Eu³⁺ in MgO-Ga₂O₃-SiO₂ glasses and GC was observed.     

Distributed-feedback laser actions in zirconia-ORMOSIL waveguides based on energy transfer between co-doped laser dyes

Laser dyes such as pyrromethene 567 (PM567), perylene red (P-red) and coumarin 540A (C540A) were doped into zirconia-organically modified silicate (ORMOSIL) materials prepared by low temperature sol-gel technique. Narrow line-width distributed feedback (DFB) laser actions were induced in the PM567 and/or P-red doped sol-gel planar waveguide. Tuning of the output wavelength was achieved by varying the period of the gain modulation generated by a nanosecond Nd:YAG laser at 532 nm. Compared with those of PM567 and P-red solely doped thin films, tuning range of C540A, PM567 and P-red co-doped sol-gel planar waveguide was greatly extended, from 564.5 nm to 635.1 nm.     

The luminescence properties of Er-doped and Er-Tm-co-doped phosphate glasses for white light emitting diode

Phosphate glasses and glass ceramics doped with Er³⁺ and co-doped with Er³⁺-Tm³⁺ are presented in this work. The luminescence properties have been characterized by absorption, excitation and emission spectra. All samples excited by blue light could emit a combination of blue/green/orange/red wavelength giving white light. For Er³⁺-doped glasses, a self-quenching effect has been obtained and an adjustable tune comes out after crystallization. For co-doped glasses, the red emission at 651 nm has been enhanced due to the existence of Tm³⁺, which could be relative to both the overlapped emissions and the energy transfer from Tm³⁺ to Er³⁺.     

Effect of some doping elements on the ionic conduction of mixed alkali-alumino-borosilicate glasses

Summary Some borosilicate glasses containing an equimolar ratio of different alkali types (K⁺ and Na⁺ ions) doped with 0.1 mole% R (R=Mn, Tb, Y, or Gd) were prepared. The results of d.c. electrical conductivity show that the absolute values of resistivities and the corresponding activation energies for the doped glasses are lower than those for glasses without doped ions. This behaviour is explained on the basis of the formation of elastic dipoles in such glasses and of the change of their fields owing to the existence of the doping ions. By thermal treatment of these glasses, it is found that the activation energies for the doped glasses are different from those obtained for glassess prepared without doping ions. This peculiarity is explained on the basis of the phase separation process in such glasses.     

高发射截面掺镱氧化物玻璃

在国外报道的一些掺镱(Yb^3 )激发玻璃基上,实验研究得到发射截面更大的掺Yb^3 玻璃.其中掺Yb^3 锗碲酸盐`硼酸盐和硅铌酸盐玻璃的发射截面大于1.9pm^2;磷酸盐玻璃的发射截面较小但有较长的荧光寿命.优良的光谱性质使这些玻璃有望成为高平均功率和高峰值功率激光器增益介质的候选基质.     

Magneto-optical investigations of rare earth doped sol-gel derived silicate xerogels

Rare-earth doped xerogels (Eu³⁺, Sm³⁺, Ho³⁺, Pr³⁺) were prepared by using the sol-gel method and their magneto-optical and optical properties have been studied. The Magnetic Circular Dichroism (MCD) spectra are quite similar to those recorded in the RE-doped fluorozirconate glasses; the fine structures shown by the MCD spectra are better resolved compared to the optical absorption spectra. The MCD technique has been correlated with optical measurements in order to investigate the site symmetry in the particular case of Eu³⁺-doped xerogel and oxyfluoride glasses. In the xerogel, coordination symmetry around the Eu³⁺ ions is close to D_3h and is lower in the oxyfluoride glass.     

Synthesis and characterization of Ce doped silica (SiO2) nanoparticles

A series of silica doped with different mol percentages of Ce³⁺ concentration was synthesized using a sol-gel method to determine the dependence of photoluminescence wavelengths and intensity on the concentrations of the dopants. Sol-gel glasses are porous networks that have been densified through chemical processing and heat treatment. Rare-earths (REs) are insoluble in silica; due to this insolubility RE ions in silicate glasses enter as network modifiers and compete for non-bridging oxygen in order to complete their coordination. The morphological, structural, thermal and optical properties of the phosphors were characterized by X-ray diffraction, scanning electron microscopy, UV-vis absorption, photoluminescence, thermogravimetric analyses and differential scanning calorimeter. Silica (SiO₂) gel containing Ce³⁺ ions was sputter coated with Au (gold) in order to monitor surface morphology of the samples. The highest emission intensity was found for the sample with a composition of 0.5 mol% Ce³⁺. Cerium doped silica glasses had broad blue emission corresponding to the ²D_3/2-²F_J transition at 448 nm but exhibited apparent concentration quenching above concentrations of 0.5 mol% Ce³⁺.     

碱土金属离子对掺铒磷酸盐玻璃除水性质的影响

以掺铒磷酸盐玻璃中铒离子寿命随OH含量变化为依据,系统研究了碱土金属离子类型和含量对磷酸盐铒玻璃除水性质的影响。结果表明,采用通干燥O2和CCl4除水工艺可有效降低玻璃中OH含量,除水效果在通气的最初阶段最为明显,玻璃中OH含量降低速率随通气时间延长而减慢,最终趋于动态平衡。值得指出的是,在相同通气时间,磷酸盐铒玻璃的荧光寿命随碱土金属离子半径增大而减短。含有较高浓度碱土金属离子的磷酸盐铒玻璃具有较短的荧光寿命,并且在停止通气后熔体重新吸水的能力变大。     

Optical properties and up-conversion of Pr doped CdS nanoparticles in sol-gel glasses

Silica glasses containing Pr³⁺ with and without CdS nanoparticles were prepared by sol-gel technique. The influence of CdS nanoparticles on Pr³⁺ doped glass was studied by absorption, photoluminescence and up-conversion. From the measured intensities of various absorption bands of these glasses, the Judd-Ofelt parameters Ω₂, Ω₄ and Ω₆ have been evaluated. The radiative transition probability (A), radiative lifetime (τ_R), branching ratio (β_R) and integrated emission cross-section (σ_P) were calculated from excited states of ³P₁ and ³P₀ levels. The up-conversion emissions were found in the green, orange and red regions under 800 nm excitation with peaks 559, 612 and 688 nm respectively. On excitation with 370 nm also leads to similar green, orange and red regions.