微波辅助液相法制备CaMoO4∶Eu3+荧光粉

采用微波辅助液相沉淀法制备了Ca1-xMoO4∶ Eu3+(0.05≤x≤0.09)系列红色荧光粉.通过荧光光谱仪、SEM、XRD测试和表征了该荧光粉的荧光性能、形貌、结构.结果表明,当Eu3+掺杂量为0.07,烧结温度为900℃,保温时间为3h时,可获得性能最佳的荧光粉,在395 nm和465 nm波长激发下,在616 nm处出现了很强的发射峰,对应于Eu3+的5D0→7F2的跃迁.采用微波辅助液相沉淀法制备的荧光粉发光强度高于高温固相法所制备的荧光粉,适合白光LED用红色荧光粉.     

熔盐法制备LaOCl∶Eu3+及其发光性能研究

以共沉淀法制备的La(OH)3∶EU3+为前驱体,采用KCl-LiCl熔盐法在700℃成功制备了掺杂均匀的LaOCl∶Eu3+的发光材料,SEM及TEM结果显示的LaOCl∶Eu3+粉体的尺寸约为1 μm～2μ,m,且形貌规整,XRD及EDS结果表明Eu3+已较好地掺入了LaOCl晶格,为制备均匀Eu3+掺杂的LaOC...     

红色Sr1-2xNaXWO4:Eu3+x荧光体的制备与发光性能

采用传统高温固相法,以钨酸锶为基质材料,掺杂稀土Eu3+制备了可被紫色光有效激发的红色荧光粉Sr1-2xNaxWO4:Eu3+x.通过测定与分析样品Sr1-2xNaxWO4:Eu3+x的激发和发射光谱,发现激发光谱在395nm处吸收值最大,发射光谱的发射主峰位于613nm处,属于Eu3+的5 D0→7F2特征跃迁.不同的Eu3+掺杂浓度下样品发光强度不同,当x =0.07时发光强度最佳.电荷补偿剂Na+对样品发光强度的影响很大,主要原因是Na+的加入会影响基质的晶体结构,当Na+的含量与Eu3+含量相同时样品发光强度最好,Na+含量增加到一定程度后基质结晶不完善,荧光体的发光强度急剧下降.     

YVO4:Er3+的合成及真空紫外发光性质的研究

经高温固相反应合成YVO4:xEr3+(x=0.001,0.003,0.005,0.007,0.01,0.03,0.05,0.07,0.09,0.1摩尔比)绿色系列粉末状发光材料.经X射线衍射分析产物为单相,属四方锆英石结构.检测了材料的真空紫外激发光谱和发射光谱.发现,YVO4:xEr3+(x=0.001,0.003...     

新型Eu3+三元复合发光材料研究

合成了一种新型三元复合物Eu^3 －AAOM－TTA[TTA：2－噻吩甲酰三氟丙酮：聚丙烯酰胺（70％）／丙烯酸（30％），数均相对分子质量为10000]并测定了其荧光光谱。该三元复合物的发光强度比强发光物质NaEu(TTA)4的荧光强度还大，而且比二元复合物Eu^3 AAOM的发光强度大20倍，研究了合成条件对复合物发光强度的影响，该三元复合物是一种潜在的优良发光材料。     

水热法制备Y2O3:Eu及其发光性能的研究

利用水热法制备立方相Y₂O₃:Eu红色荧光粉.在不同掺杂浓度、不同溶液pH值的系列样品中,均观测到Eu3+离子的特征发射.荧光强度与Eu3+离子掺杂浓度关系研究表明:在不同掺杂浓度中,Eu3+离子掺杂浓度为9 %时其相对发射强度最强.在不同溶液pH值所获得的样品中,以溶液pH等于6制备的样品发光效果最好.此外通过与商用Y₂O₃:Eu红色荧光粉比较,发现其荧光强度相当.因此,与传统高温固相法相比,水热法合成Y₂O₃:Eu红色荧光粉是简单易行方案.      

Eu~(3+)∶ZnO_(1-x)S_x-SiO_2发光材料的制备与发光性质

采用溶胶凝胶法与沉淀法相结合的方法,制备Eu3+∶ZnO1-xSx-SiO2红色发光材料,通过DTA-TG、IR、XRD、TEM、EDS、激发和发射光谱等测试手段,研究材料的结构和发光性能。DTA-TG结果表明,样品在400℃以上,样品结构基本达到稳定状态;IR测试表明,样品中主要存在Si-O-Si键、Zn-S键、Si-O4基团,温度达到800℃时Zn-S键变强,且Si-O-Si三维网络结构的形成有利于Eu3+的掺杂和发光;1000℃时Si-O4基团发生分裂现象,分为三个峰,同时部分ZnS被氧化为ZnO,该变化破坏了SiO2形成的大的三维网络结构,使Si-O-Si桥氧键断开,形成非桥氧键,此结构不利于Eu3+的发光,说明800℃时样品的发光性能最好。XRD测试表明,样品属于晶态,主要以ZnO、ZnS、Zn2SiO4的形式存在。TEM和EDS结果表明,样品呈类球状,含有Zn、O、Si、Eu、S元素,其中S的含量约为2.40%(原子分数),说明S被有效地掺入样品中。激发和发射光谱测试表明,在612 nm检测波长下,其最佳激发波长为紫外光395 nm,最佳退火温度为800℃,Eu3+最佳掺杂量为10%(原子分数),并证明Eu3+∶ZnO1-xSx-SiO2材料发光强度约是Eu3+∶ZnO-SiO2发光强度的6倍,说明S的引入可以有效的提高发光性能。     

掺杂Eu3+离子的钨酸锂的固相合成及其发光特性

采用固相反应法合成了掺杂Eu3 的Li2WO4材料,并通过X射线粉末衍射对其结构进行了表征,掺杂Eu3 的Li2WO4的晶体结构属四方晶系,晶胞参数a=14.2780 ,c=9.5863 ,属R3(No.148)空间群,测定了其激发光谱和发射光谱,探讨了掺杂Eu3 的Li2WO4的发光特性。     

共沉淀法制备长余辉发光材料CaWO4:Eu3+的研究

用共沉淀法制备CaWO4:Eu3 纳米长余辉发光材料.用XRO表征了所得长余辉发光材料的形态和物相组成,用荧光分光光度计测定了长余辉发光材料的发光性能.确定了用共沉淀法制备CaWO4:Eu3 长余辉发光体的最佳条件,其最佳煅烧温度为700℃,煅烧时间为2h.结果表明,共沉淀法制备的CaWO4:Eu3 长余辉发光材料比高温固相法所得材料有更好的长余辉性能.     

掺杂Eu3+离子的YPO4的合成及其发光特性

用BPO4和稀土氧化物为原料，采用固相反应法合成了掺杂Eu^3 离子的YPO4，并用X射线粉末衍射对其结构进行了表征，X射线粉末衍射实验结果表明，YPO4属四方晶系，晶胞参数α=0.6894nm,c=0.6020nm，属I41/αmd(No.141)空间群，测定了其激发光谱和发射光谱，探讨了掺杂Eu^3 离子的YPO4的发光特性。     

Red-emitting CaWO4:Eu3+,Tm3+ phosphor for solid-state lighting: Luminescent properties and morphology evolution

CaWO₄:xEu³⁺,yTm³⁺crystals were obtained by facile synthesis at low temperature by the microwaveassisted hydrothermal method(MAH).The phase formation,morphology,luminescent properties and ene rgy transfer were investigated.The X-ray diffraction(XRD)re sults show the formation of a scheelitelike tetragonal structure without the presence of secondary phases.The growth mechanism of hierarchical micro structures based on self-assembly and Ostwald-ripening processes was evaluated,obtaining different types of morphologies.The luminescence spectra of CaWO₄:Eu³⁺,Tm³⁺at 325 nm excitation show the predominance of red emission at the 5 D0→7 F2(Eu³⁺)transition at 624 nm.This feature signals dominant behavior of the electric dipole type.The presence of Tm³⁺is notably evident in the absorption spectra by the related excitation transitions:3 H6→1 G4,3 H6→3 F3 and 3 H6→3 H4.Color parameters are discussed to characterize CaWO₄:Eu³⁺,Tm³⁺emission.The study of the emission spectrum as a function of the concentration of Eu³⁺(x mol%)and Tm³⁺(y mol%)indicates that the CaWO₄:Eu³⁺,Tm³⁺phosphors show stronger red emission intensity and exhibit the CIE value of x=0.63 and y=0.35.The photoluminescence results show 97%high color purity for CaWO₄:4 mol%Eu³⁺,a high CRI(92%)and a low CCT of 1085 K.These results demonstrate that the CaWO₄:Eu³⁺,Tm³⁺red phosphors are promising as color converters for application in white light-emitting diodes and display devices.     

Preparation and Luminescent Characteristics of LaPO4∶Eu Nanoparticles and Nanowires

Nanoparticles and nanowires of LaPO4: Eu phosphors were synthesized by hydrothermal method. Their luminescent properties including electronic transition, surface effect, and temperature-dependent luminescent characteristics were systemically studied and compared to the bulk powders. It can be concluded that in comparison with the bulk powders, the fluorescence intensity decreases in nanoparticles and nanowires, while the lifetime increases, indicating that the radiative transition rate decreases. The nonradiative transition rate in nanowires decreases than that in nanoparticles due to its decreased surface to volume ratio. The temperature-dependent experiments indicate that the thermal quenching in nanopowders becomes weaker than that in the bulk powders.     

Eu3+激活的Li2Gd4（MoO4）7钼酸盐红色荧光体及其发光性质

由高温固相反应首次合成Li2(Gd1-xEux)4(MoO4)7(0相似文献   

Sol-Gel Synthesis and Luminescent Characteristic of Doped Eu^3 ＋ Silicate-Silica Phosphor

Silicagelphosphorsdopedrareearthionshave attractedgreatattentionofmanyresearchersdueto theseadvantages,suchashighersamplehomogeneity,purityandstable,efficientandenvironmentallyfriend lyphotoluminescencematrixmaterials,whichisless toxicleadtonetconversione…     

Luminescent characteristics of LiCaBO3：Eu^3＋ phosphor for white light emitting diode

LiCaBO3:Eu3+ phosphor was synthesized by high solid-state reaction method, and its luminescent characteristics were investigated. The emission and excitation spectra of LiCaBO3:Eu3+ phosphors exhibited that the phosphors could be effectively excited by near ultraviolet (400 nm) and blue (470 nm) light, and emitted red light. The effect of Eu3+ concentration on the emission spectrum of LiCaBO3:Eu3+ phos-phor was studied. The results showed that the emission intensity increased with increasing Eu3～ concentration, and then decreased because of concentration quenching. It reached the maximum at 3mol.% Eu3+, and the concentration self-quenching mechanism was the d-d interaction according to the Dexter theory. Under the conditions of charge compensator Li+, Na+ or K+ incorporated in LiCaBO3, the emission intensities of LiCaBO3:Eu3+ phosphor were enhanced.     

Eu2+、Er3+共掺杂Sr3MgSi3O10高亮度蓝色荧光粉的制备及性质研究

采用凝胶-燃烧法在活性炭弱还原气氛下成功合成了高亮度蓝色发光材料Sr3 MgSi3 O10:Eu2+,Er3+.用X射线粉末衍射仪、荧光分光光度计对样品的物相结构和发光性质进行了分析和表征.结果表明,所合成的Sr3 MgSi3O10:Eu2+,Er3+的晶体结构与Sr2 MgSi2 O7的相似,属四方晶系.样品激发光谱是位于250 nm～450 nm的宽带,最大激发峰位于357 nm处;发射光谱也是一宽带,最强的发射峰位于466 nm处,属于Eu2+典型的4f65d1→4f7跃迁,呈蓝光发射.根据光谱测定结果和Van Uitert经验公式,推断Eu2+进入Sr3 MgSi3 O10基质后占据八配位Sr的格位.研究发现,共掺杂Er3+能有效敏化Sr3 MgSi3 O10基质中Eu2+的发光,当Er3+的掺杂摩尔分数为0.04时,样品发光强度最大,约为单掺Eu2+样品发光强度的3.3倍.