新型WLED荧光粉Ca2MgSi2O7:Ce3+,Eu2+的能量传递和光色研究

用高温固相法制备了 Ca2 MgSi2O7:Ce3+,Eu2,并研究其发光特性.Ce3+的发射带峰值位于410 nm,对应于Ce3+的5d→4f跃迁;Eu2+的发射带峰值位于530 nm,对应于Eu2+的5d→4f跃迁.双掺样品的发射光谱表明两种离子间存在高效的电偶极-电偶极能量传递.当Ce3+和Eu2浓度分别为2％和0.125％时,样品发射光谱(λex=360 nm)色坐标为(0.221,0.312),落在白光区.以上研究说明Ca2 MgSi2O7:Ce3+,Eu2+是一种适用于近紫外芯片的新型WLED荧光粉,其光色可调谐.     

Sr4Al14O25:Eu2+长余辉发光材料浓度淬灭研究

采用固相法制备Sr4Al14O25∶Eu2 长余辉发光粉体. 研究了Eu2 离子在铝酸盐基体中的发光行为以及浓度淬灭过程与淬灭机制. 结果表明, Eu2 在基体中形成两种不同发光中心, 分别为Eu1和Eu2, 具有不同的配位数. 在紫外光激发后, 发射波长分别为400 nm和486 nm. Eu2 离子在Sr4Al14O25中的浓度淬灭包含两个不同的淬灭过程. 随着Eu2 离子浓度的增大, Eu1格位的发光通过将能量传递给Eu2而产生淬灭现象. 随着Eu2 离子浓度的继续增大, Eu2格位的发光通过将能量传递给周围晶格缺陷而淬灭. 从实验和理论计算的结果来看, Eu2 离子在Sr4Al14O25∶Eu2 中的能量传递方式有两种, 一是光能的重吸收, 二是通过电子偶极-偶极作用交互方式传递能量.     

白光LED用新型红色荧光粉KCaY(MoO4)3:Eu3+的制备及发光性能

采用高温固相法制备了新型KCaY1-x(Mo04)3:Eux红色荧光粉.利用X射线衍射(XRD)、扫描电镜(SEM)和荧光光谱技术对粉体进行了结构、表面形貌和发光性能表征.结果表明:该系列荧光粉均为四方晶系的白钨矿结构,能够被近紫外光(394 nm)和蓝光(465 nm)有效激发,产生Eu3的5 D0→7 F2特征跃迁红光发射(613 nm).对这种荧光粉作后处理,可改善其表面形貌,并提高其发光强度.该系列荧光粉在394,465 nm的吸收与目前广泛应用的近紫外和蓝光LED芯片的输出波长相匹配.因此这种荧光粉是一种可能应用在白光LED上的红色荧光粉材料.     

白光LED用红色荧光粉CaWO_4:Eu~(3+),Li~+,Bi~(3+)的制备与表征

采用预先球磨、再二次热处理的高温固相合成法,制备了一系列白光LED用红色荧光粉CaWO4:Eu3+,L i+,B i3+,利用XRD,SEM和荧光光谱测试对其进行表征。XRD分析表明,所合成的样品为单一的四方晶系CaWO4,Eu3+,L i+,B i3+离子的先后掺杂使基质的部分衍射峰峰位向小角度移动;SEM照片显示,经过预先球磨制备的样品颗粒比较均一,尺寸约为0.5~3μm范围,结晶性好;荧光光谱测试发现这一系列荧光粉不仅可以被紫外光(254 nm)激发,还能被近紫外光(393 nm)和蓝光(465 nm)有效激发,其主发射峰值位于616 nm(Eu3+离子的5D0→7F2跃迁)的红光;另外详细研究了预先球磨的效果、加入H3BO3做助熔剂的质量分数以及Eu3+,L i+,B i3+离子单掺或多掺时的浓度对该体系荧光粉发光特性的影响。     

Tb4O7纯度对Tb3Al5O12发光性质的影响

采用溶胶－凝胶法用不同纯度的Tb4O7在非还原气氛下合成了Tb3Al5O12，并研究了最佳合成条件，电子能谱以及发光性质，结果表明：Tb3Al5O12最佳合成时间应不超过3h，最佳合成温度不超过900℃，提高Tb4O7的纯度，Tb3Al5O12中Tb^3 的发光明显增强。     

共掺杂稀土配合物Tb0.5Eu0.5(asprin)3phen电致发光的研究

合成了共掺杂稀土配合物Tb0.5Eu0.5(asprin)3phen，将其掺杂到导电聚合物PVK中，制成结构为ITO／PVK：RE配合物／PBD／Al的电致发光器件，与PVK：Eu(asprin)3phen体系为发光层的相同结构的器件相比，我们发现铽离子的引入能猝灭PVK的发光，增强铕的发光，而Tb3 本身的发光很弱，几乎看不到，说明Pb3 在其中起到能量的中间传递作用，促进了PVK到Eu^3 的能量传递，本文就器件的发光特性及掺杂体系的能量传递进行了初步讨论。     

Fe3O4@YF3:Eu3+双功能复合颗粒的制备与性能研究

采用直接沉淀法合成了Fe3 O4@ YF3:Eu3核壳结构磁性-荧光性双功能纳米复合颗粒,对其结构和性能进行了表征.XRD分析表明,得到了结晶良好的尖晶石型Fe3 O4纳米晶和正交相的YF3纳米晶.TEM照片表明,双功能复合颗粒具有明显的核壳结构.构成核的Fe3 O4纳米颗粒尺寸在40 ～80nm之间.Fe3 O4@ YF3:Eu3+核壳结构复合纳米颗粒的尺寸约为100 ～250 nm,壳层YF3:Eu3+厚度介于20 ～30 nm之间.EDS分析表明样品由Y,F,Eu,O和Fe元素组成.荧光光谱和磁性测试结果表明,复合颗粒同时具有良好的发光性和较强的磁性,使其在生物医学领域具有潜在的应用.     

Yb3+和Er3+共掺的GdAlO3荧光粉体的发光性质研究

采用溶胶-凝胶法制备了Yb3+和Er3+掺杂的GdAlO3荧光粉体.XRD结果表明样品为正交晶系结构.研究了不同波长激发下的室温发射光谱以及上转换发光光谱.结果表明样品在1550 nm处有很强的荧光发射,并且在样品中存在显著的Yb3+到Er3+之间的能量传递过程.980 nm红外光激发下的上转换发光光谱表明样品有绿色和...     

Optical Spectroscopy and Excited-State Dynamics of Eu3+-Doped Bismuth Borate Glasses Containing CuO

Bismuth borate glasses containing phosphors and luminescent rare-earths are of interest for applications in light-emitting devices. Herein, the influence of CuO impurities on red-emitting Eu³⁺-doped bismuth borate glasses of the 25Bi₂O₃-15BaO-10Li₂O-50B₂O₃ type was investigated by various spectroscopic methods. The glasses were prepared by the melt-quench technique and characterized by X-ray diffraction (XRD), Fourier transform-infrared (FT-IR) spectroscopy, UV/Vis optical absorption (OA), and photoluminescence (PL) spectroscopy including decay kinetics assessment. The XRD data confirmed the amorphous nature of the glasses whereas FT-IR spectra indicated the basic structural features of trigonal BO₃ units and BO₄ tetrahedra. The OA analysis showed that addition of CuO up to 0.5 mol% results in significant growth of the visible Cu²⁺ absorption band around 715 nm, with slight decrease in the optical band gap energies assessed through Tauc plots. A drastic PL quenching of Eu³⁺ ions emission was evidenced concurring with the detrimental effect of Cu²⁺. The assessment of the Eu³⁺ emission decay curves revealed significant lifetime decrease of the ⁵D₀ emitting state with increasing CuO concentration. An analysis of quenching constants was finally performed comparing results from integrated PL data with the emission decay rates. It is argued that the bismuth borate glass system supports an effective Eu³⁺→Cu²⁺ energy transfer (more so than phosphates) in connection with a strong spectral overlap between Eu³⁺ emission and Cu²⁺ absorption.     

Synthesis,Persistent Luminescence,and Thermoluminescence Properties of Yellow Sr3SiO5:Eu2+,RE3+ (RE=Ce,Nd, Dy,Ho, Er,Tm, Yb) and Orange‐Red Sr3−xBaxSiO5:Eu2+, Dy3+ Phosphor

Sunlight‐excitable orange or red persistent oxide phosphors with excellent performance are still in great need. Herein, an intense orange‐red Sr_3?xBa_xSiO₅:Eu²⁺,Dy³⁺ persistent luminescence phosphor was successfully developed by a two‐step design strategy. The XRD patterns, photoluminescence excitation and emission spectra, and the thermoluminescence spectra were investigated in detail. By adding non‐equivalent trivalent rare earth co‐dopants to introduce foreign trapping centers, the persistent luminescence performance of Eu²⁺ in Sr₃SiO₅ was significantly modified. The yellow persistent emission intensity of Eu²⁺ was greatly enhanced by a factor of 4.5 in Sr₃SiO₅:Eu²⁺,Nd³⁺ compared with the previously reported Sr₃SiO₅:Eu²⁺, Dy³⁺. Furthermore, Sr ions were replaced with equivalent Ba to give Sr_3?xBa_xSiO₅:Eu²⁺,Dy³⁺ phosphor, which shows yellow‐to‐orange‐red tunable persistent emissions from λ=570 to 591 nm as x is increased from 0 to 0.6. Additionally, the persistent emission intensity of Eu²⁺ is significantly improved by a factor of 2.7 in Sr_3?xBa_xSiO₅:Eu²⁺,Dy³⁺ (x=0.2) compared with Sr₃SiO₅:Eu²⁺,Dy³⁺. A possible mechanism for enhanced and tunable persistent luminescence behavior of Eu²⁺ in Sr_3?xBa_xSiO₅:Eu²⁺,RE³⁺ (RE=rare earth) is also proposed and discussed.     

GdPO4∶Eu3+和GdPO4∶Ce3+,Tb3+纳米晶多元醇法的合成与表征

首次采用多元醇的方法合成了GdPO4:Eu3+和GdPO4:Ce3+,Tb3+纳米晶,并利用X-射线衍射(XRD),傅立叶变换红外光谱(FTIR),透射电镜(TEM),光致发光光谱(PL)及热重和差示扫描量热分析(TG-DSC)对产物进行了表征.结果表明,产物为单斜晶系独居石结构正磷酸盐;形貌为梭形,长轴600～700 nm,短轴50～200 nm;纳米晶在水中有良好的分散性.GdPO4:Eu3+水溶液在251 nm激发下.发射光谱以Eu3+的5D0-7F1 (592 nm)磁偶极跃迁强度最大;GdPO4:Ce3+,Tb3+纳米晶水溶液的激发光谱在240～300nm处有一宽的吸收带,峰值位于262 nm,为Ce3+离子的4f-5d跃迁吸收,发射光谱呈现Tb3+特征绿色发射,最强峰位于544 nm.讨论了GdPO4:Ce3+,Tb3+体系中敏化发光机理,通过光谱分析证实了存在Ce3+→Gd3+→Tb3+的能量传递过程.     

(CaO)20.68(MgO)1.32(SiO2)4S2∶Eu2+,Dy3+红光材料的制备与发光特性

研究了峰值波长651nm的红色发光材料(CaO)20.68(MgO)1.32(SiO2)4S2∶Eu2 ,Dy3 的制备及发光特性。通过XRD分析表明硫气氛中合成的材料为具有硫成分的硅酸盐相。红光发射带为硫元素进入晶格后在发光中心周围形成了类似长余辉材料CaS∶Eu2 ,Cl-的局域结构。这也使材料具有了硫化物长余辉材料的发射光谱特征和硅酸盐材料高化学稳定性和高亮度的优点。热释光测量揭示它可能是一种潜在的红色长余辉材料。     

LaF3:Eu3+纳米粒子的水热法制备及发光性质研究

用水热法制备了LaF3及Eu^3＋掺杂的LaF3纳米粒子, 通过X射线粉末衍射（XRD）、透射电子显微镜（TEM）和荧光光谱（FS）对样品进行了表征. 结果表明： 所得的纳米粒子粒度均匀、结晶完好, 呈规则的六边形形状;研究了反应温度和时间对LaF3纳米粒子形成的影响, 初步探讨了纳米粒子的生长机制. 研究了掺杂Eu^3＋后的发光性质, 发现纳米粒子经高温煅烧后, 荧光强度有明显下降, 适宜的煅烧条件为600 ℃/6 h, Eu^3＋的掺杂量在5%（摩尔分数）时, 纳米粒子的荧光强度最强, 更高的掺杂浓度将导致荧光猝灭.     

Eu2+ & Mn2+‐Coactivated Ba3Gd(PO4)3 Orange‐Yellow‐Emitting Phosphor with Tunable Color Tone for UV‐Excited White LEDs

A novel orange‐yellow‐emitting Ba₃Gd(PO₄)₃:x Eu²⁺,y Mn²⁺ phosphor is prepared by high‐temperature solid‐state reaction. The crystal structure of Ba₃Gd(PO₄)₃:0.005 Eu²⁺,0.04 Mn²⁺ is determined by Rietveld refinement analysis on powder X‐ray diffraction data, which shows that the cations are disordered on a single crystallographic site and the oxygen atoms are distributed over two partially occupied sites. The photoluminescence excitation spectra show that the developed phosphor has an efficient broad absorption band ranging from 230 to 420 nm, perfectly matching the characteristic emission of UV‐light emitting diode (LED) chips. The emission spectra show that the obtained phosphors possess tunable color emissions from yellowish‐green through yellow and ultimately to reddish‐orange by simply adjusting the Mn²⁺ content (y) in Ba₃Gd(PO₄)₃:0.005 Eu²⁺,y Mn²⁺ host. The tunable color emissions origin from the change in intensity between the 4f–5d transitions in the Eu²⁺ ions and the ⁴T₁‐⁶A₁ transitions of the Mn²⁺ ions through the energy transfer from the Eu²⁺ to the Mn²⁺ ions. In addition, the mechanism of the energy transfer between the Eu²⁺ and Mn²⁺ ions are also studied in terms of the Inokuti–Hirayama theoretical model. The present results indicate that this novel orange‐yellow‐emitting phosphor can be used as a potential candidate for the application in white LEDs.     

Color Point Tuning in Lu3−x−yMnxAl5−xSixO12:yCe3+ for White LEDs

A series of the solid‐solution phosphors Lu_3?x?yMn_xAl_5?xSi_xO₁₂:yCe³⁺ is synthesized by solid‐state reaction. The obtained phosphors possess the garnet structure and exhibit similar excitation properties as the phosphor Lu₃Al₅O₁₂:Ce³⁺, but with an effectively improved red component in the emission spectrum. This can be attributed to the energy transfer from Ce³⁺ to Mn²⁺. Our investigation reveals that electric dipole–quadrupole interactions dominate the energy‐transfer mechanism and that the critical distance determined by the spectral overlap method is about 9.21 Å. The color‐tunable emissions of the Lu_3?x?yMn_xAl_5?xSi_xO₁₂:yCe³⁺ phosphor as a function of Mn₃Al₂Si₃O₁₂ content are realized by continuously shifting the chromaticity coordinates from (0.354, 0.570) to (0.462, 0.494). They indicate that the obtained material may have potential application as a blue radiation‐converting phosphor for white LEDs with high‐quality white light.     

溶胶-凝胶法合成(Ce, Tb)GdMgB5O10及其发光性质的研究

利用溶胶-凝胶法合成了纯的GdMgB5O10及GdMgB5O10：Ce^3 ，Tb^3 粉末；利用X射线衍射(XRD)、扫描电镜(SEM)、发光光谱等测试手段对GdMgB5O10以及GdMgB5O10：Ce^3 ，Tb^3 粉末的物相、形貌、发光性质等进行了研究。XRD和SEM结果表明溶胶-凝胶法适合制备GdMgB5O10，且在800℃焙烧时完成结晶，颗粒尺寸为200～300nm。发光光谱的测试表明：Tb^3 呈现其特征绿光发射，最强峰位于543nm，在GdMgB5O10：Tb^3 中，当236nm激发时其最佳掺杂摩尔分数为16％。通过光谱分析进一步证实了GdMgB5O10：Ce^3 ，Tb^3 中存在的能量传递过程为：Ce^3 将能量传递给Gd^3 ，然后能量在Gd^3 次晶格中经若干次迁移，最后被Tb^3 捕获。     

Mono- and Mixed Metal Complexes of Eu3+, Gd3+, and Tb3+ with a Diketone,Bearing Pyrazole Moiety and CHF2-Group: Structure,Color Tuning,and Kinetics of Energy Transfer between Lanthanide Ions

Three novel lanthanide complexes with the ligand 4,4-difluoro-1-(1,5-dimethyl-1H-pyrazol-4-yl)butane-1,3-dione (HL), namely [LnL₃(H₂O)₂], Ln = Eu, Gd and Tb, were synthesized, and, according to single-crystal X-ray diffraction, are isostructural. The photoluminescent properties of these compounds, as well as of three series of mixed metal complexes [Eu_xTb_1-xL₃(H₂O)₂] (Eu_xTb_1-xL₃), [EuxGd_1-xL₃(H₂O)₂] (Eu_xGd_1-xL₃), and [Gd_xTb_1-xL₃(H₂O)₂] (Gd_xTb_1-xL₃), were studied. The Eu_xTb_1-xL₃ complexes exhibit the simultaneous emission of both Eu³⁺ and Tb³⁺ ions, and the luminescence color rapidly changes from green to red upon introducing even a small fraction of Eu³⁺. A detailed analysis of the luminescence decay made it possible to determine the observed radiative lifetimes of Tb³⁺ and Eu³⁺ and estimate the rate of excitation energy transfer between these ions. For this task, a simple approximation function was proposed. The values of the energy transfer rates determined independently from the luminescence decays of terbium(III) and europium(III) ions show a good correlation.     

新型双钼酸盐红色荧光粉的制备及发光性能研究

采用高温固相法合成了一种新型的白光LED用双钼酸盐红色荧光粉,利用XRD,F-4500等对其进行了研究。结果表明:该系列荧光粉可以被近紫外光(396 nm)和蓝光(466 nm)有效激发,发射峰值位于615 nm(Eu3+离子的5D0→7F2跃迁)的红光;而且在钾铕双钼酸盐荧光粉KEu(MoO4)2中引入适量的钨酸能加强其发光强度,而不改变样品的发射光谱的形状和发射峰的位置。此外,在确定WO24-/MoO42最佳比值的前提下,文章还详细探讨了碱金属离子相互置换对样品发光性能影响的机制。     

掺杂Tb3+离子的CaxSr1-xWO4的合成及其性质研究

采用固相反应法合成了掺杂Tb^3 离子的CaSr1-xWO4荧光体，并通过X射线粉末衍射对其结构进行了表征，研究结果表明：系列CaxSr1-xWO4荧光体属四方晶系，属I41/a空间群，CaWO4与SrWO4可形成良好的混合的固溶体，且晶胞参数随组成呈线性变化规律，测定了其激发光谱和发射光谱，探讨了掺杂Tb3 离子的CaxSr1-xWO4荧光体的发光特性。     

Eu3+掺杂ZMCB和ZMLB基光致发光玻璃纤维性能的研究

在发光粉废料处理中发现用高温固相反应和玻璃流股牵引方法,人工拉制了Eu3 掺杂ZnO-MgO-CdO-B2O3基质的光致发光玻璃纤维,直径为0.01～0.30 mm,长10余米.Eu3 离子613 nm的强发射归属于5D0-7F2电偶极跃迁,相对613 nm发射强度40%的591 nm发射归属于5D0-7F1磁偶极跃迁.说明Eu3 在局域环境中主要占据非对称中心格位.对不同浓度Eu3 的光衰曲线进行拟合,发现随着掺杂Eu3 浓度的增加,发光由单指数衰减变为双指数衰减.用SEM观察到玻璃纤维的表面光滑、低析晶、断口质密度高、断口贝纹呈明显沟状.并测试了发光玻璃纤维的一系列力学参数,也研究了Eu3 掺杂ZnO-MgO-La2O3-B2O3基玻璃纤维的光谱性能.