白光LED用MMoO_4∶Eu~(3+)红色荧光粉制备工艺研究

用溶胶-凝胶优化法合成了红色荧光粉MMoO4∶Eu3+(M=Ca、Sr、Ba),通过SEM、PL表征了荧光粉的形貌及发光性能。结果表明:烧结温度为800℃时,颗粒粒度分布均匀,粒径约为0.5-1μm,有很好的分散性;掺杂0.25molEu2O3在395nm和464nm两主激发峰下,均可得到616nm处红光发射极峰,属于Eu3+典型的5 D0→7F2的跃迁所致;助熔剂NH4F明显提高了钼酸盐荧光粉的发光强度;通过比较M0.5MoO4∶Eu03.+25,Li0+.25(M=Ca、Sr、Ba)发光性能得知:在395nm激发下,Ca0.5MoO4∶Eu30.+25,Li0+.25荧光粉最有利于提高发光强度。     

Emission analysis of Sm3+:Ca4GdO(BO3)3 powder phosphor

This paper reports on the spectral analysis of reddish orange color luminescent Sm³⁺:Ca₄GdO(BO₃)₃ powder phosphor. This phosphor powder has been synthesized by a solid state reaction method. Emission spectrum of it has shown four emission transitions of ⁴G_5/2 → ⁶H_J (J = 5/2, 7/2, 9/2, 11/2) and among them, the transition ⁴G_5/2 → ⁶H_7/2 displays the reddish orange (605 nm) color. Lifetimes of three emissions (⁴G_5/2 → ⁶H_{J=5/2, 7/2 & 9/2}) have been computed based on the measured decay curves. Besides the measurement of emission spectrum of this material, its nature and structural details have also been investigated from XRD, SEM and FTIR studies.     

Screen-printed phosphor coatings for white LED emission

We demonstrate the possibilities offered by the screen-printing technique to create thick layers of rare earth doped phosphors on glass slides for light-emitting diodes (LEDs). Using commercial LEDs, the effect of the layer thickness and phosphor concentration on luminescence emission and chromaticity are investigated. The advantages offered by screen-printed multi-phosphors systems are also revealed through a feasibility study permitting to tune the chromatic coordinate of the global light emission by modifying the phosphors characteristics independently.     

Synthesis and photoluminescence properties of NaLaMgWO6:RE3+ (RE = Eu,Sm, Tb) phosphor for white LED application

Single phase of NaLa_1?xMgWO₆:xRE³⁺ (0 < x ≤1) (RE = Eu, Sm, Tb) phosphors were prepared by solid-state reaction method. X-ray diffraction, scanning electron microscopy, the morphology energy-dispersive X-ray spectroscopy, UV–vis diffuse reflectance spectra and photoluminescence were used to characterize the samples. Under the light excitation, NaLaMgWO₆:Eu³⁺, NaLaMgWO₆:Sm³⁺ and NaLaMgWO₆:Tb³⁺, phosphors showed the characteristic emissions of Eu³⁺ (⁵D₀ → ⁷F_{4, 3, 2, 1}), Sm³⁺ (⁴G_5/2 → ⁶H_{5/2, 7/2, 9/2}), and Tb³⁺ (⁵D₄ → ⁷F_{6, 5, 4, 3}), respectively. The intensity of the red emission for Na(La_0.6Eu_0.4)MgWO₆ is 2.5 times higher than that of (Y_0.95Eu_0.05)₂O₃ under blue light irradiation. The quantum efficiencies of the entitled phosphors excited under 394 nm and 464 nm are also investigated and compared with commercial phosphors Y₂O₃:Eu³⁺, Sr₂Si₅N₈:Eu²⁺ and Y₃A₅G₁₂:Ce³⁺. The results demonstrated NaLaMgWO₆:RE³⁺ phosphors as potential candidates for white light emitting diode pumped by UV or blue chip.     

Preparation and photoluminescence properties of CaSc2O4:Eu3+ red phosphor for white LEDs

Journal of Materials Science: Materials in Electronics - The development of red phosphors has a significant impact on high-quality white LEDs lighting. In this research, the luminous properties of...     

BaMg2(PO4)2:Sm3+红色荧光粉发光性质的研究

采用高温固相法合成了BaNg2(PO4)2:Sm3+红色荧光材料发光材料并对其发光特性进行了研究.该荧光粉有三个主要发射峰,分别位于564 nm、600 nm、648 nm,对应于4G5/2→6H5、4G5/2→6H7、4G5/2→6H9/2的跃迁发射,其中600 nm处发射最强,呈现红色发光.随着Sm3+浓度的增加,...     

白光LED用稀土红色荧光粉的研究进展

白光LED具有低压、低功耗、高可靠性和长寿命等一系列优点,是一种符合环保和节能的绿色照明光源。现阶段制造高显色指数、低色温,大功率白光LED是白光LED发展的总体趋势。而红色荧光粉性能对白光LED的显色指数及色温的影响极其显著。本方法着重介绍和评述了白光LED用红色荧光粉硫化物、氮化物、钼酸盐和钨酸盐等几大主要体系的发光性质及最新研究成果和发展现状,并对白光LED用荧光粉的发展进行了展望。     

Y2O3:Eu3+ phosphor: a novel solution for an increase in color rendering index of multi-chip white LED packages

Abstract

In this study, a novel compound is synthesized by adding the red-emitting Y₂O₃:Eu³⁺ dopant to conformal phosphor package (CPP) or in-cup phosphor package (IPP), to be employed as a component in multi-chip white LEDs lamps (W-LEDs). It was found that this solution can enhance the color rendering index (CRI) of W-LEDs that have correlated color temperatures of 5600 K through 8500 K to more than 86. Besides, the impacts of the Y₂O₃:Eu³⁺ phosphor on the attenuation of light through the phosphor layers, CPP and IPP, are also demonstrated based on the Beer–Lambert law and Mie theory. These results provide important information for producing W-LEDs with higher CRI.     

Pr3+摩尔浓度对CaTiO3:Pr3+红色长余辉材料的影响

制备了不同Pr^3 摩尔浓度下的CaTiOs：Pr^3 红色长余辉材料，测量了磷光体的的初始亮度、余辉曲线、激发光谱和发射光谱、热释光曲线。研究发现CaTiO3：Pr^3 合适的Pr^3 摩尔浓度为0．1％—0．2％，在该摩尔浓度下，材料具有较好初始亮度和余辉时间。     

LED用YAG:Ce3+荧光粉包覆SiO2膜的研究

选用热稳定性好、无色透明的SiO2为包覆物,采用溶胶法,以正硅酸乙酯(TEOS)为硅源,对YAG:Ce3+荧光粉的表面进行SiO2膜的包覆研究,以解决LED荧光粉在使用过程中突出的热劣化问题.采用X射线衍射(XRD),扫描电子显微镜(SEM),透射电子显微镜(TEM)和荧光光谱(FS)等对包膜前后的YAG:Ce3+荧光...     

Photoluminescence properties of green-emitting Eu2+-activated Ba3Si6O12N2 oxynitride phosphor for white LED applications

Eu²⁺-activated Ba₃Si₆O₁₂N₂ green-emitting phosphors were synthesized by a solid-state reaction method. X-ray diffraction patterns showed that the synthesized phosphor sintered at 1200 °C for 12 h was a Ba₃Si₆O₁₂N₂ pure phase. The synthesized phosphors were excited in UV to blue light. The emission spectra showed a broad green emission band when excited with a light at 465 nm. The highest emission intensity was observed at a Eu²⁺ concentration of 0.25 mol and the NH₄Cl concentration of the optimized flux was found to be 9 wt.%. The obtained green-emitting Ba₃Si₆O₁₂N₂:Eu²⁺ phosphors could be applied to white LED applications.     

Photoluminescence and quenching study of the Sm3+-doped LiBaPO4 phosphor

Journal of Materials Science: Materials in Electronics - Sm3+-doped LiBaPO4 phosphors have been successfully synthesized by solution combustion method. As prepared samples were characterized by...     

白光LED用单一基质白光荧光粉的研究进展

白光LED以其独特优势被称为第四代光源,具有广阔的应用前景。单一基质白光荧光粉(SMWP)因颜色稳定、色彩还原性好,成为白光LED用光转换材料的研究热点。概述了由近紫外LED芯片激发的白光荧光粉的研究现状,指出了该荧光粉存在的问题并对其发展趋势做了展望。     

Methods to improve the fluorescence intensity of CaS:Eu red-emitting phosphor for white LED

In order to improve the fluorescence intensity of red-emitting phosphor based on alkaline earth sulfide CaS:Eu²⁺ for white LED (light-emitting diode), many methods were used. When the flux is NH₄F, auxiliary activator is Er³⁺, intensity of phosphor CaS:Eu²⁺ has the strongest brightness. On the other hand, introduction of Sr could make the maximum excitation band shift to high energy, which make the phosphor match well with blue light GaN-based LED; Mg partly substitute for the alkaline earth Ca could make the intensity of red emitting phosphor increase greatly.