Tb~(3+)、Gd~(3+)对硅酸盐发光玻璃发光性能的影响

对Nb3 + 激活的硅酸盐发光玻璃进行了研究 ,讨论了Tb3+ 和Gd3 + 对玻璃发光性能的影响。结果表明 :Tb3+ 激活的硅酸盐玻璃在紫外线和X 射线的激发下 ,产生蓝色荧光和较强的绿色荧光 ;随着Tb3+ 离子浓度的增加 ,Tb3 + 离子5D3 能级的能量向5D4 能级转移 ,绿色荧光得到增强 ;Gd3 + 离子通过无辐射能量共振方式对Tb3+ 离子的发光起到了敏化作用 ,加入Gd3+ 进一步提高了Tb3+ 激活硅酸盐玻璃的发光强度     

Tb3＋自敏化效应与Gd3＋-Tb3＋能量转移对硅酸盐玻璃发光性能的影响

研究了Tb3+自敏化效应与Gd3+-Tb3+能量转移对硅酸盐玻璃发光性能的影响.结果表明,随着Tb3+掺杂量的增加,Tb3+的400～450 nm蓝色荧光发射减弱,而485 nm和545 nm绿光发射增强.Tb3+掺杂硅酸盐玻璃中,Tb3+之间存在能量转移,产生自敏化效应,这种转移是由Tb3+之间电偶极-电四极的相互作用引起的共振能量转移.Gd3+通过Gd3+-Tb3+间的能量转移对Tb3+的发光起敏化作用,这种能量转移主要是偶极与偶极相互作用引起的共振转移.     

Li2SrSiO4:Eu2+,Tb3+中Eu2+和Tb3+的发光特性和能量传递

用高温固相法在N2/H2=95/5(v/v)还原气氛下合成了Li2SrSiO4:Eu2+,Tb3+荧光粉发光材料,通过荧光光谱研究其发光特性,并从理论上探讨了Eu2+与Tb3+之间的能量转移类型。结果表明:该发光材料主发射峰值550nm,与Eu2+在4f7-4f65d1产生跃迁有关;通过掺杂,共存于Li2SrSiO4基质中的Tb3+通过电多级相互作用将能量传递给Eu2+;在500~650nm范围内对Eu2+具有很强的敏化作用,使其在主发射峰550nm的发射强度显著增强;当名义化学组成为Li2Sr0.995SiO4:0.005Eu2+,0.010Tb3+时,发光强度为最佳。     

新型GdAlO3：RE荧光粉多元掺杂及发光机制研究

采用柠檬酸盐硝酸盐燃烧法制备GaAlO3：RE荧光粉体．在紫外光激发T(254m)发现Pr共掺杂对GaAlO3：Eu红色荧光粉体发光有降低作用；Ce共掺杂对GaAlO3：Tb绿色荧光粉体发光有降低作用．激发谱研究表明，共掺杂时分别存在Eu→Pr、Tb→Ce的声子支持的共振能量传递，造成GaAlO3：Eu、GaAlO3：Tb荧光粉体发光强度降低．     

Gd3+/Ce3+对Tb3+掺杂氟氧化物玻璃发光敏化作用的影响

本文采用高温熔融法制备了Gd/Tb、Gd/Ce、Gd/Ce/Tb掺杂的SiO₂-B₂O₃-BaF₂组分氟氧化物玻璃,通过测试X射线衍射光谱确定了其物相,通过测试其不同波段激发下的荧光光谱研究了不同Gd₂O₃掺量下Tb³⁺的发光性能,并确定了Gd₂O₃更精确的最佳掺量范围。此外,文中通过改变气氛制备了Gd/Ce/Tb共掺杂氟氧化物玻璃,对比研究了Gd³⁺和Ce³⁺对Tb³⁺的敏化作用。结果表明,本文所制备的氟氧化物玻璃都呈稳定的玻璃态;Gd³⁺和Ce³⁺对Tb³⁺的发光都具有敏化作用,且Gd₂O₃掺量为7%(摩尔分数,下同)时敏化效果相较于其他掺量最为显著,超出7%则造成猝灭;Ce₂O_3<...     

Mn2+对掺Ce3+BiB3O6纳米材料发光强度的影响

采用溶胶-凝胶的方法合成了一系列掺杂Mn2+,Ce3+的BiB3O6纳米发光材料.通过激发光谱和发射光谱研究了其发光性质,并探讨了Mn2+对Ce3+发光性能的影响.BiB3O6:Ce3+的发射光谱有位于370nm和405nm处的2个发射峰,由于Mn2+对Ce3+的敏化作用,Ce3+在BiB3O6:Ce3+,Mn2+中的发光强度有了显著的增强.     

掺杂RE3+对CaAl2O4:Eu2+,Nd3+发光性能的影响

以燃烧法合成了CaAl2O4∶Eu2+,Nd3+,RE3+紫色长余辉发光材料。实验结果表明,掺杂辅助激活剂Pr3+和Ce3+对CaAl2O4∶Eu2+,Nd3+磷光体发光性能有明显影响。掺杂Pr3+的CaAl2O4∶Eu2+,Nd3+样品的发射峰蓝移;掺杂Ce3+的CaAl2O4∶Eu2+,Nd3+样品的发射峰红移。Pr3+或Ce3+掺杂,可以提高CaAl2O4∶Eu2+,Nd3+磷光体的初始亮度,Pr3+或Ce3+在其中起到增加陷阱密度,提高发光亮度的作用。     

Ca_3Sc_2Si_3O_12:Ce~(3+),Nd~(3+)近红外荧光粉的制备和发光性质

利用高温固相法在弱还原气氛中制备了Ca3-x-ySc2Si3O12:xCe3+,yNd3+近红外发光荧光粉。用X射线衍射确定了样品的相结构,并研究了样品的可见及近红外激发和发射光谱,发光强度,荧光寿命等随Ce3+,Nd3+掺杂量的变化。结果表明:Ca3-x-ySc2Si3O12:xCe3+,yNd3+体系中Ce3+的发射光谱和Nd3+的激发光谱的有效重叠,说明存在Ce3+到Nd3+的高效能量传递,Ce3+,Nd3+的掺杂量分别为x=0.1和y=0.07时,Ca3-x-ySc2Si3O12:xCe3+,yNd3+粉体具有最强的近红外发射。与单掺Na3+的样品相比,Ca3Sc2Si3O12中掺杂Ce3+和Nd3+后,样品的近红外发光增强近400倍。此外,初步分析了Ca3-x-ySc2Si3O12:xCe3+,yNd3+中Ce3+到Nd3+的能量传递机理。     

水热法制备SrF2:Ce3+,Tb3+荧光粉及其发光性质研究

采用水热法合成了具有立方相结构的Ce3+、Tb3+共掺杂的SrF2发光材料SrF2:Ce3+,Tb3+,利用粉末X-射线衍射( XRD)对其结构进行了表征,并研究了掺杂量、水热反应时间、激发波长对SrF2:Ce3+,Tb3+发光性质的影响.荧光光谱研究结果表明,SrF2:Ce3+,Tb3+在254 nm波长紫外光激发下...     

LaPO_4∶Ce~(3+),Tb~(3+)荧光屏的制备及表征

采用重力沉积法在石英基片上涂敷LaPO4∶Ce3+,Tb3+荧光粉制备了LaPO4∶Ce3+,Tb3+荧光屏。通过X射线衍射仪、扫描电子显微镜(SEM)和荧光分光光度计对荧光屏进行表征,研究了黏结剂、电解质、荧光粉的用量对荧光屏性能的影响。结果表明:调整黏结剂、电解质的用量可制备荧光粉和基片结合良好的荧光屏,荧光屏的主晶相仍为LaPO4。SEM分析表明荧光涂层致密、均匀,厚度约为40μm。荧光光谱分析表明,在200~300nm紫外光激发下可发射主发射峰为543nm的绿色荧光。随黏结剂用量的增加,发光强度先增大后减小,性能最佳的黏结剂体积浓度为3%;随电解质用量的增加,发射光强度先增高后降低,当其质量分数为0.01%时,发光强度最大;随着荧光粉用量的增加,透过荧光屏的发射光强度降低。     

稀土离子(Ce3+,Tb3+, Pr3+)掺杂重金属锗酸盐玻璃的光谱透过及抗辐射性能

从新型抗辐射闪烁体材料的应用背景出发，对某些稀土离子掺杂重金属锗酸盐玻璃进行了紫外与可见光谱区的透过性能及抗辐射性能的表征，重点讨论玻璃基质组成与短波截止波长之间的关系以及一些元素对玻璃抗辐射性能的影响。玻璃基质组成涉及GeO2，Gd2O3，BaO，SnO，La2O3，掺杂的稀土元素包括Ce^3 ，Tb^3 ，Pr^3 。实验结果表明：这些重金属锗酸盐玻璃的紫外截止波长适中(350min)，适于用作掺杂稀土离子的基质材料。Sn^2 和Ce^3 使玻璃的紫外截止波长明显红移，其原因与特殊的紫外吸收机理有关。在所加入的元素中，Sn^2 和稀土离子Ce^3 ，Tb^3 ，Pr^3 均对玻璃的抗辐射性能有增强作用，其中以Ce^3 抗辐射效应最为明显，这主要归因于这些离子的变价特性。     

Size and shape controllable synthesis and luminescent properties of BaGdF5:Ce3+/Ln3+ (Ln = Sm, Dy, Eu, Tb) nano/submicrocrystals by a facile hydrothermal process

In this paper, we present a facile and environmentally-friendly hydrothermal process to synthesize BaGdF(5): 2.5 mol% Ce(3+)/2.5 mol% Ln(3+) (Ln = Sm, Dy, Eu and Tb) nano/submicroparticles. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), as well as photoluminescence (PL) spectra are used to characterize the resulting samples. The size, shape, and composition of the products could be tuned just by varying the organic additives and the pH values of the initial reaction solutions. The morphologies for the products include nanospheres, submicrospheres, peanut-like particles, as well as the spindle-like and star-like aggregates. Moreover, the size of the samples can be tuned from 50 nm to 150 nm. Additionally, we systematically investigate the luminescence properties of different lanthanide ions in BaGdF(5) host. Under single-wavelength excitation at 260 nm, the samples doped with different lanthanide ions show intensive multicolor visible emissions depending on the doped Ln(3+) ions. The luminescence process can be attributed to the strong absorption of UV irradiation by Ce(3+) ions, followed by energy transfer to Gd(3+) ions, from which the energy is transferred to Ln(3+), resulting in the emission from the luminescent Ln(3+) centers. The Gd(3+) ions play an intermediate role in this process.     

Room temperature synthesis of hydrophilic Ln(3+)-doped KGdF4 (Ln = Ce, Eu, Tb, Dy) nanoparticles with controllable size: energy transfer, size-dependent and color-tunable luminescence properties

In this paper, we demonstrate a simple, template-free, reproducible and one-step synthesis of hydrophilic KGdF(4): Ln(3+) (Ln = Ce, Eu, Tb and Dy) nanoparticles (NPs) via a solution-based route at room temperature. X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) and cathodoluminescence (CL) spectra are used to characterize the samples. The results indicate that the use of water-diethyleneglycol (DEG) solvent mixture as the reaction medium not only allows facile particle size control but also endows the as-prepared samples with good water-solubility. In particular, the mean size of NPs is monotonously reduced with the increase of DEG content, from 215 to 40 nm. The luminescence intensity and absolute quantum yields for KGdF(4): Ce(3+), Tb(3+) NPs increase remarkably with particle sizes ranging from 40 to 215 nm. Additionally, we systematically investigate the magnetic and luminescence properties of KGdF(4): Ln(3+) (Ln = Ce, Eu, Tb and Dy) NPs. They display paramagnetic and superparamagnetic properties with mass magnetic susceptibility values of 1.03 × 10(-4) emu g(-1)·Oe and 3.09 × 10(-3) emu g(-1)·Oe at 300 K and 2 K, respectively, and multicolor emissions due to the energy transfer (ET) process Ce(3+)→ Gd(3+)→ (Gd(3+))(n)→ Ln(3+), in which Gd(3+) ions play an intermediate role in this process. Representatively, it is shown that the energy transfer from Ce(3+) to Tb(3+) occurs mainly via the dipole-quadrupole interaction by comparison of the theoretical calculation and experimental results. This kind of magnetic/luminescent dual-function materials may have promising applications in multiple biolabels and MR imaging.     

溶胶凝胶法制备的Y3Al5O12:Tb3+,Ce3+的光学性能及能量传递研究

用溶胶凝胶法制备了一系列不同掺杂浓度的Y3Al5O1 2(YAG):Tb3+,Ce3+荧光粉,对其物相、光学性能和能量传递进行了研究.多晶粉末X-射线衍射结果表明,所有样品均为YAG晶相,没有其它杂相.当样品在Tb3+的特征激发峰273 nm激发时,除了Tb3+的特征发射外,还观察到位于467 nm的YAG基质的电荷迁...     

Photodarkening mechanisms of Pr3+ singly doped and Pr3+/Ce3+ co-doped silicate glasses and fibers

In this work, we revealed the possible mechanisms of the photodarkening in Pr³⁺ ions singly doped and Pr³⁺/Ce³⁺ co-doped silicate glasses and fibers induced by X-ray and 488-nm laser radiations and studied the role of Ce³⁺ in increasing radiation resistance in Pr³⁺-doped silicate glasses and fibers. The absorption, emission, electron paramagnetic resonance (EPR), radiation induced attenuation spectra, and X-ray photoelectron spectroscopy (XPS) of Pr³⁺ singly doped and Pr³⁺/Ce³⁺ co-doped silicate glasses before and after X-ray radiation were measured and analyzed. The fluorescence intensity and photoinduced attenuation of Pr³⁺ singly doped and Pr³⁺/Ce³⁺ co-doped silicate fibers at visible wavelengths pumped by 488-nm laser were measured and analyzed. The influence of Ce³⁺ ions co-doping on the spectroscopic properties of Pr³⁺ ions as well as the radiation-induced defects in silicate glasses was studied. Results demonstrate that both X-ray and 488-nm laser radiations will induce photodamage in Pr³⁺ ions-doped silicate glasses and fibers. Co-doping Ce³⁺ (by up to 1 mol%) is efficient to suppress the darkening induced by both X-ray and 488-nm laser radiations without influence on the luminescence behavior of Pr³⁺ ions in silicate glasses and fibers. Our studies demonstrate the promising potential of Pr³⁺/Ce³⁺ co-doped silicate glasses for visible lasing applications.     

Modification of Optical Properties of SrAl_2O_4：Eu~（2＋）,Dy~（3＋） Phosphor by Terbium Doping

以尿素为燃料,采用快速燃烧法在650℃合成了Tb3＋掺杂的SrAl2O4：Eu2＋,Dy3＋新型长余辉光致发光材料。研究了Tb3＋掺杂对Eu2＋,Dy3＋共激活的铝酸盐长余辉发光材料的发光特性的影响。X射线衍射分析结果表明：当Tb3＋的掺杂量x=0.17%时,合成的样品结构为单相SrAl2O4单斜晶系。光致发光测试结果表明：样品的激发光谱为峰值位于345nm附近的连续宽带谱,发射光谱为峰值位于510nm左右的连续宽带谱。余辉衰减曲线结果表明：Tb3＋的适量掺杂可以提高铝酸锶的余辉性能。与SrAl2O4：Eu2＋,Dy3＋相比,掺杂Tb3＋有利于形成结晶度良好的固溶体,样品中的晶体细密紧凑,颗粒粒径约为100nm。     

Eu‐, Tb‐, and Dy‐Doped Oxyfluoride Silicate Glasses for LED Applications

Luminescence glass is a potential candidate for the light‐emitting diodes (LEDs) applications. Here, we study the structural and optical properties of the Eu‐, Tb‐, and Dy‐doped oxyfluoride silicate glasses for LEDs by means of X‐ray diffraction, photoluminescence spectra, Commission Internationale de L'Eclairage (CIE) chromaticity coordinates, and correlated color temperatures (CCTs). The results show that the white light emission can be achieved in Eu/Tb/Dy codoped oxyfluoride silicate glasses under excitation by near‐ultraviolet light due to the simultaneous generation of blue, green, yellow, and red‐light wavelengths from Tb, Dy, and Eu ions. The optical performances can be tuned by varying the glass composition and excitation wavelength. Furthermore, we observed a remarkable emission spectral change for the Tb³⁺ single‐doped oxyfluoride silicate glasses. The ⁵D₃ emission of Tb³⁺ can be suppressed by introducing B₂O₃ into the glass. The conversion of Eu³⁺ to Eu²⁺ takes place in Eu single‐doped oxyfluoride aluminosilicate glasses. The creation of CaF₂ crystals enhances the conversion efficiency. In addition, energy transfers from Dy³⁺ to Tb³⁺ and Tb³⁺ to Eu³⁺ ions occurred in Eu/Tb/Dy codoped glasses, which can be confirmed by analyzing fluorescence spectra and energy level diagrams.