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1.
采用高温固相法合成了SrB4O7∶Eu荧光粉,并研究了不同原料、掺杂浓度、煅烧温度等因素对其发光性能的影响。发射光谱测试结果表明:SrB4O7∶Eu荧光粉的最佳Eu掺杂浓度为2%左右,进一步增大掺杂浓度会导致浓度猝灭。煅烧温度对基质组成影响较大,随着温度的升高,基质中BO4四面体所占比例增大,有利于Eu3+离子的还原。以水合硼酸锶为原料制得样品的发光强度高于以SrCO3和H3BO3为原料制得样品的发光强度。  相似文献   

2.
刘林峰  吕树臣 《发光学报》2009,30(2):228-232
利用共沉淀法制备了纳米晶Gd2O3 : Eu3+发光粉体。 在不同掺杂浓度、不同煅烧温度的系列样品中,均观测到Eu3+离子的特征发射。样品的晶相与发射性质的研究表明:所制备的样品经800~1 300 ℃热处理后,晶相为立方相,1 400 ℃时开始向单斜相转变。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+离子浓度为4%时其相对发射强度最强。在三个不同的煅烧温度中,经800 ℃煅烧的样品其发光效果最好。此外还观察到电荷转移激发态以及基质、Gd3+与Eu3+之间的能量传递。激发谱包含三部分,即电荷转移带、Eu3+的4f内壳层电子跃迁和Gd3+的激发谱。  相似文献   

3.
采用溶胶-凝胶法制备出BaGd1-xEuxB9O16红色磷光粉,对过程的物料配比、前驱体处理和晶化温度等制备条件进行了讨论。结果表明,样品在850 ℃下开始晶化,900 ℃时就能够获得较好的晶化产物,结合不同晶化温度下的发光强度比较确定,晶化温度为950 ℃时,BaGd1-xEuxB9O16磷光粉具有较高的结晶状态和发光强度。当Eu浓度x=0.9时具有最大的发光强度;初始原料配比硼酸须按计量过量15%。所得荧光粉的激发光谱峰值为264,394,465,534 nm等,分别归属于Eu-O电荷迁移带及Eu3+7F0-5L67F0-5D27F0-5D1跃迁,发射光谱呈Eu3+的特征红光,最强的发射峰位于614 nm,归属于5D0-7F2跃迁。进一步研究表明该磷光粉中存在着Gd3+对Eu3+的能量传递。  相似文献   

4.
以硝酸镁、钨酸钠为原料,氢氧化钠和硝酸作为pH调节剂,在180~230 ℃水热条件制备纯相的MgWO4。探讨了水热反应温度对MgWO4纯相形成以及煅烧温度对其晶型、发光性质的影响。分别用粉末X射线衍射、荧光光谱、扫描电子显微镜和综合热分析等手段对样品进行表征。结果表明,水热法可以直接制得不含结晶水MgWO4晶体,属于四方晶系,形貌呈片状,厚度约为几个纳米。样品热重分析和高温煅烧的结果表明,水热法所得MgWO4晶体在850 ℃附近出现晶型转化,由四方晶系转变为单斜晶系,并导致发光性质的明显变化。SEM显示煅烧前的样品形貌为片状,不同温度煅烧后由片状逐渐向棒状转变。  相似文献   

5.
采用高温固相法制备了AlF3-YbF3∶Er3+上转换荧光粉,分析了Er3+掺杂浓度对其发光强度的影响。通过X-ray diffraction (XRD)对样品物相分析。利用荧光发射光谱研究了该荧光粉的上转换发光性能,进而提出其上转换能量传递机理,研究结果表明:在980 nm半导体激光器激发下,以AlF3-YbF3为基质,当Er3+的掺杂浓度为0.7 mol%时,该荧光粉的红光发射强度最强;通过上转换发光强度与泵浦电流关系曲线的拟合,表明AlF3-YbF3∶Er3+上转换荧光粉的红光上转换过程为双光子过程。  相似文献   

6.
以脲素为燃烧剂,采用燃烧法在较低引发温度下快速合成了CaAl12O19xMn4+发光粉体。采用正交分析法考查了煅烧温度、Mn4+掺杂量、燃烧剂用量和煅烧时间等合成条件对荧光粉发光强度的影响。实验结果表明:煅烧温度1 200 ℃,Mn4+掺杂量2%,燃烧剂/CaAl12O19摩尔比为50∶1, 煅烧时间5 h为最佳合成工艺,制得的荧光粉的发射强度为95.8。该荧光粉由于Mn4+的2E—4A2跃迁,在643和656 nm呈现强红色发光,其中656 nm为最大发射峰;在470 nm处的最大激发峰是属于Mn4+配位场的4A2—4T2跃迁,470 nm激发峰可以与LED芯片的465 nm发射相匹配。  相似文献   

7.
周鹤  周志勇  曾群  姚春凤  刘磊 《发光学报》2018,39(7):909-914
采用溶胶-凝胶法制备Li1.0Nb0.6Ti0.5O3:Eu3+红色荧光粉,讨论了煅烧温度、煅烧时间以及Eu3+掺杂浓度对样品发光性能的影响。通过XRD、荧光光谱分别对样品的性能进行表征,结果表明:样品的晶相结构为"M-相(M-phase)"。在466 nm蓝光激发下,合成的荧光粉具有橙光(593 nm)和红光(612 nm)发射。发光强度随着煅烧温度的升高先增大后减小,最佳的煅烧温度为850℃。同时,随着煅烧时间的增加,发光强度先增大后减小,最佳煅烧时间为6 h。当Eu2O3掺入质量分数为2.5%时,样品的发光强度达到最大。Li1.0Nb0.6-Ti0.5O3:Eu3+红色荧光粉在白光LED的应用中具有潜力。  相似文献   

8.
YVO4·xTiO2 : Eu3+荧光粉的发光性质   总被引:1,自引:1,他引:0       下载免费PDF全文
采用高温固相方法合成了YVO4 ·xTiO2 : Eu3+(x=0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9)粉末状发光材料,经X射线衍射分析结构发现材料为两相共存。一相为YVO4,属四方锆英石结构;另一相为Y2Ti2O7,属立方烧绿石结构。研究了YVO4 ·xTiO2 : Eu3+在UV及VUV激发下的光谱性质,讨论了Ti 的掺杂对材料发光性能的影响,发现适量的Ti的掺入可以提高材料 基质对UV及VUV的吸收。在UV及VUV激发下,YVO4· xTiO2 : Eu3+荧光粉的发射光谱主峰在616 nm和619 nm,证明Eu3+占据了晶格中非反演对称中心的位置。在YVO4 ·xTiO2 : Eu3+的激发光谱中,有一中心位于155 nm的吸收带,它属于基质的吸收带。  相似文献   

9.
以亚甲基双丙烯酰胺为网络剂,采用高分子网络凝胶法合成了Sr2CeO4∶Dy3+荧光粉,并表征其结构、颗粒形貌及发光性能。研究结果表明:Sr2CeO4∶Dy3+无其他杂相存在且粉末颗粒大小均匀。其紫外-可见吸收带集中在480 nm附近;在370 nm紫外光激发下,其发射图谱为一多峰发射;监测470 nm的发射峰,所得样品的激发谱为一双峰宽谱,峰位为292和338 nm。同时研究了Dy3+掺杂浓度对样品发射光谱的影响,结果显示,随着Dy3+浓度的增大,其黄、蓝发射峰强度比值逐渐增大,但发光强度呈现先增大后减小的趋势,在Dy3+掺杂浓度为0.4 mol%时达到最大值。  相似文献   

10.
通过溶胶-凝胶法制备出不同Tb3+掺杂浓度和不同二次煅烧温度下的ZnAl2O4:Tb3+荧光粉, 并利用X射线衍射(XRD)和荧光光谱等对样品进行了表征。由XRD结果可知,当Tb3+掺杂的摩尔分数不大于9%,二次煅烧温度在600℃以上时,所得粉体为结晶性良好的尖晶石相。在紫外光激发下,ZnAl2O4:Tb3+荧光粉的发射光谱由位于488 nm(5D47F6)、542 nm(5D47F5)、587 nm(5D47F4 )和621.5 nm(5D47F3)的4个发射峰组成。研究发现,Tb3+的掺杂浓度和二次煅烧温度对样品发光强度有着重要影响,当Tb3+的摩尔分数为5%,二次煅烧温度为900℃时,ZnAl2O4:Tb3+荧光粉的发光最强,继续增加Tb3+掺杂浓度或提高煅烧温度,分别会出现浓度猝灭和温度猝灭现象。  相似文献   

11.
Gd2O3:Eu3+ (4 mol%) co-doped with Bi3+ (Bi = 0, 1, 3, 5, 7, 9 and 11 mol%) ions were synthesized by a low-temperature solution combustion method. The powders were calcined at 800°C and were characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), Fourier transform infrared and UV–Vis spectroscopy. The PXRD profiles confirm that the calcined products were in monoclinic with little cubic phases. The particle sizes were estimated using Scherrer’s method and Williamson–Hall plots and are found to be in the ranges 40–60 nm and 30–80 nm, respectively. The results are in good agreement with TEM results. The photoluminescence spectra of the synthesized phosphors excited with 230 nm show emission peaks at ~590, 612 and 625 nm, which are due to the transitions 5D07F0, 5D07F2 and 5D07F3 of Eu3+, respectively. It is observed that a significant quenching of Eu3+ emission was observed under 230 nm excitation when Bi3+ was co-doped. On the other hand, upon 350 nm excitation, the luminescent intensity of Eu3+ ions was enhanced by incorporation of Bi3+ (5 mol%) ions. The introduction of Bi3+ ions broadened the excitation band of Eu3+ of which a new strong band occurred ranging from 320 to 380 nm. This has been attributed to the 6s2→6s6p transition of Bi3+ ions, implying a very efficient energy transfer from Bi3+ ions to Eu3+ ions. The gamma radiation response of Gd2O3:Eu3+ exhibited a dosimetrically useful glow peak at 380°C. Using thermoluminescence glow peaks, the trap parameters have been evaluated and discussed. The observed emission characteristics and energy transfer indicate that Gd2O3:Eu3+, Bi3+ phosphors have promising applications in solid-state lighting.  相似文献   

12.
《Current Applied Physics》2015,15(6):748-752
Eu3+-doped Ba0.7Sr0.3TiO3 thin films were prepared by a chemical solution deposition method and characterized by X-ray diffraction, field emission scanning electron microscopy, photoluminescence and dielectric measurements. The thin films were well crystallized with a pure perovskite structure. A contraction of the unit cell was observed upon incorporation of Eu3+ ions below 2 mol%, while an expansion occurred as the Eu3+ concentration was further increased above 2 mol%, indicating that Eu3+ ions with different concentrations occupied different lattice sites. Photoluminescence spectra showed two prominent transitions of Eu3+ ions at 594 nm (5D0 → 7F1) and 618 nm (5D0 → 7F2) upon excitation at 395 nm (7F0 → 5L6). There existed two quenching concentrations at 2 mol% and 4 mol% due to different lattice sites of the Eu3+ ions. We also investigated the dielectric properties of the thin films. Our study suggests that Eu3+-doped Ba0.7Sr0.3TiO3 thin films have potential applications in multifunctional optoelectronic devices.  相似文献   

13.
红色LiMBO3 : Re3+(Re=Eu,Sm) 发光材料的特性   总被引:2,自引:1,他引:1       下载免费PDF全文
采用固相法制备了红色LiM(M=Ca, Sr, Ba)BO3 : Re3+(Re=Eu, Sm)发光材料,研究了材料的发光性能。研究发现LiM(M=Ca, Sr, Ba)BO3 : Eu3+材料呈现多峰发射,最强发射分别位于610,615,613 nm处,分别监测这三个最强峰,所得激发光谱峰值位于369,400,470 nm。LiM(M=Ca, Sr, Ba)BO3 : Sm3+材料也呈多峰发射,分别对应Sm3+4G5/26H5/24G5/26H7/24G5/26H9/2跃迁发射;分别监测602,599,597 nm三个最强发射峰,所得激发光谱峰值位于374,405 nm。研究了激活剂浓度对材料发射强度的影响,结果随激活剂浓度的增大,发射强度先增强后减弱,即,存在浓度猝灭效应。实验表明,加入电荷补偿剂Li+、Na+或K+均可提高LiM(M=Ca, Sr, Ba)BO3 : Re3+(Re=Eu, Sm)材料的发射强度。  相似文献   

14.
Hexagonal YPO4 phosphors doped with Eu3+/Dy3+ and co-doped with Ce3+ were synthesized by a hydrothermal route assisted using lauric acid as a capping agent. The prepared phosphors were characterized by transmission electron microscopy, infrared spectroscopy, powder X-ray diffraction and photoluminescence spectra. YPO4: Eu3+ gives two red emission peaks at 587 and 610?nm corresponding to 5D07F1 and 5D07F2 transitions, respectively. YPO4: Dy3+ exhibits two emission peaks at 485?nm (blue) and 575?nm (yellow) corresponding to 4F9/26H15/2 and 4F9/26H13/2 transitions, respectively. Ce3+ ions enhanced the emission intensity as a co-dopant in both phosphors. Moreover, the effect of γ-radiation in the dose range 5–300?kGy on the photoluminescence behaviour of YPO4:Eu3+,Ce3+ and YPO4:Dy3+,Ce3+ was also investigated. Quenching of emission intensity, after irradiation at 5 and 300?kGy, was observed in both the phosphors due to loss of excess energy through a non-radiative relaxation process.  相似文献   

15.
Excitation and luminescence spectra of RbCl co-doped with divalent and trivalent europium ions are reported. Spectral dips appearing in the blue emission from Eu2+ are resulted from the radiative energy transfer from Eu2+ to Eu3+ and consequently induces the luminescence from Eu3+ that is responsible for the 5D07FJ (J=0, 1, 2, 3, 4) transitions. The induced luminescence has been characterized as a function of temperature and a decay time. In addition, the polarized emission from RbCl doped with only Eu2+ is also reported.  相似文献   

16.
张桂兰  陈亭  陈文驹  洪广言 《物理学报》1988,37(12):2004-2010
本工作测量了室温下TbP3O14和EuP5O14晶体的吸收和发射光谱。根据吸收光谱和Judd-Ofelt理论计算了Tb3+和Eu3+的实验和理论的振子强度。用最小二乘法拟合实验与理论的振子强度得到唯象强度参量Ωλ。然后计算了Tb3+5D37F5,5D47F45D47F6以及Eu3+5D07F2,5D07F4的跃迁几率和寿命。同时用时间分辨光谱测量了不同温度下相应的荧光辐射寿命。计算与实验结果基本相符。理论和实验的结果表明Tb3+5D3态的寿命主要取决于5D35D47F67F0两能级对之间的电偶极-电偶极交叉弛豫。 关键词:  相似文献   

17.
Photoluminescence and excitation spectra of the spinel-type MgGa2O4 with 0.5 mol. % Mn2+ ions and Eu3+ content from 0 to 8 mol. % have been investigated in this work at room temperature. Polycrystalline samples were synthesized via high-temperature solid-state reaction method. Photoluminescence spectra of all samples exhibit host emission presented by a broad “blue” band peaking ∼430 nm, which consists of at least three elementary bands that correspond to different host defects. Excitation of the host luminescence showed the broad band with a maximum at 360 nm. Characteristic bands of d–d transitions of Mn2+ ions and f–f transitions of Eu3+ ions together with charge-transfer bands (CTB) of these ions were also found on the excitation spectra. Mn2+ and Eu3+ co-doped samples emit in green and red spectral regions. Mn2+ ions are responsible for the green emission band at 505 nm (4Т16А1 transition). The studies of photoluminescence spectra of activated samples with different Eu3+ ions content show characteristic f–f luminesecence of Eu3+ ions. The maximum of Eu3+ emission was found at 618 nm (5D07F2) and optimal concentration of activator ions was around 4 mol. %.  相似文献   

18.
We have studied the luminescent properties of Eu2+/3+ and Yb2+ ions in strontium hexaborate SrB6O10 for excitation in the 120–400 nm region. The luminescence spectra of Ln2+ ions in SrB6O10 consist of overlapping bands in the 370–520 nm region, due to 5d → 4f transitions at several nonequivalent centers. In the excitation spectra, besides the bands associated with 4f → 5d transitions in the Ln2+ ions, we also observe a band in the 135–160 nm region due to the transitions O(2p) → B(2s,2p) within the borate anions. The luminescence of the Eu3+ ions is excited most efficiently in the region of the Eu3+ charge transfer band (λmax = 226 nm). The results obtained are compared with data for Ln in other strontium borates. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 770–774, November–December, 2006.  相似文献   

19.
Eu3+-doped β-Ga2O3 nanofibers were fabricated by electrospinning. The influence of Eu3+ concentration on the photoluminescence properties of the obtained nanofibers was investigated. The morphology and structure of β-Ga2O3:Eu3+ were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and Raman spectra. The diameter of the Eu3+-doped β-Ga2O3 nanofibers was in the range of 180-300 nm. When the β-Ga2O3:Eu3+ nanofibers were excited by 325 nm wavelength, the main emission peak of the samples was 620 nm (5D07F2), which corresponded to a typical red emission (5D07Fj (j = 1, 2, 3, 4) intra-4f transitions of Eu3+ ions). In addition, the concentration quench effect and energy transfer mechanism in β-Ga2O3:Eu3+ were also discussed.  相似文献   

20.
This paper reports on the photoluminescence (PL) and time-resolved properties of Ce3+, Eu3+, and Tb3+ in novel LiSr4(BO3)3 powder phosphors. Ce3+ shows an emission band peaking at 420 nm under 350-nm UV excitation. Energy transfer from Ce3+ to Mn2+ takes place in the co-doped samples. Eu3+ shows red emission under near UV excitation. LiSr4(BO3)3:Eu3+ phosphor could be a suitable candidate for phosphor-converted solid state lighting. The luminescence lifetime is 2.13 ms for Eu3+ in LiSr4(BO3)3:0.001Eu3+. As Eu3+ concentration increasing, the decay curves deviate from exponential behavior. Tb3+ shows the strongest 5D47 F5 emission line at 540 nm. Decay curves of 5D47 F5 and 5D37 F5 emission with different Tb3+ concentrations were also measured. Cross-relaxation process is discussed based on the decay curves.  相似文献   

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