Yb^(3+)/Nd^(3+)掺杂对Sr_(9)Ga(PO_(4))_(7)∶Cr^(3+)发光性能的影响

近红外荧光粉由于其独特的物理特性和广阔的应用前景吸引了人们极大的研究兴趣。本文通过高温固相反应法合成Sr_(9)Ga(PO_(4))_(7)∶0.8Cr^(3+)近红外荧光粉,使用460 nm蓝光激发样品的发射波长位于833 nm,半峰宽为117 nm。随后引入稀土离子合成Sr_(9)Ga(PO_(4))_(7)∶0.8Cr^(3+),Yb^(3+)和Sr_(9)Ga(PO_(4))_(7)∶0.8Cr^(3+),Nd^(3+)近红外荧光粉。相比Sr_(9)Ga(PO_(4))_(7)∶0.8Cr^(3+),460 nm蓝光激发的Sr_(9)Ga(PO_(4))_(7)∶0.8Cr^(3+),Yb^(3+)同时出现Cr^(3+)和Yb^(3+)特征发射峰,经过光谱分析和荧光寿命变化证明Cr^(3+)-Yb^(3+)存在能量传递通道,最高使Cr^(3+)-Yb^(3+)能量传递效率达80.2%,得益于Yb^(3+)卓越的热稳定性促使整体荧光光谱热稳定性提高约3.7倍。设计合成的Sr_(9)Ga(PO_(4))_7∶0.8Cr^(3+),Nd^(3+)样品调制出833,876,1 060 nm的多峰发射,显著拓宽了近红外光谱范围。最终,讨论了荧光粉在温度传感和无损检测领域的应用,证明该系列荧光粉具有广阔的应用前景。

Lu^(3+)掺杂Na_(5)Y_(9)F_(32)∶Ho^(3+)/Yb^(3+)/Ce^(3+)单晶体的增强红色上转换发光与光学温度传感性能

采用密封的坩埚下降法技术生长了一系列Lu^(3+)(摩尔分数0、0.6%、1.2%、1.8%)掺杂Na_(5)Y_(9)F_(32)∶Ho^(3+)/Yb^(3+)/Ce^(3+)单晶体。在980 nm LD激发下,观察到单晶体的绿光543 nm(^(5)S_(2)/^(5)F_(4)→^(5)I_(8))、红光656 nm(^(5)F_(5)→^(5)I_(8))以及近红外750 nm(^(5)S_(2)/^(5)F4→^(5)I_(7))上转换发光。从上转换发光强度随激发光强度的变化情况,确定了543 nm、656 nm与750 nm的发光为双光子跃迁过程。研究了Lu^(3+)离子掺杂浓度对其发光强度与荧光寿命的影响情况,随着Lu^(3+)掺杂浓度从0增加到1.8%,单晶体中的656 nm红光逐步增强,543 nm绿光与750 nm近红外光随之减弱,红绿光强度比从0.01增加到了1.55,而543 nm荧光寿命从1.29 ms降低至0.99 ms。Lu^(3+)离子的掺入取代Y^(3+)晶格位,改变了单晶体的局域场环境,导致上转换发光强度的变化。基于随温度变化的上转换红光656 nm(^(5)F5→^(5)I8)与绿光543 nm(^(5)S_(2)/^(5)F4→^(5)I8)的发光强度变化,研究了1.8%Lu^(3+)掺杂Na_(5)Y_(9)F_(32)∶Ho^(3+)/Yb^(3+)/Ce^(3+)单晶体在298~448 K范围内的绝对灵敏度和相对灵敏度最大值分别为0.242%·K^(-1)和0.217%·K^(-1)。

动态缺陷导致Na_(3)Sc_(2)(PO_(4))_(3):Yb^(3+),Er^(3+)材料上转换和下转移发光不同热猝灭行为研究

掺Eu^(2+)的离子导体Na_(3)Sc_(2)(PO_(4))_(3)具有优异的抗热猝灭性能,是一种很有前景的大功率照明用发光材料。然而,其负热猝灭机理仍有待深入研究。本文以Yb^(3+)/Er^(3+)的f-f跃迁上转换和下转移窄带发射而非更易受干扰的Eu^(2+)d-f跃迁发射为研究对象,旨在获得更清晰的机理。结果表明,热致缺陷/离子的动态迁移能促进高温下辐射跃迁和抑制非辐射跃迁,导致上转换发光具有显著的负热猝灭,下转移发光热猝灭较小。其中,布居速率较慢的上转换过程更容易受到时间尺度与之相当的Na^(+)/空位迁移过程的影响。本研究可为理解发光材料热猝灭机制提供另一种视角。

Ce^(3+)-Tb^(3+)共掺杂黄磷炉渣微晶玻璃的发光与能量传递

以黄磷炉渣为原料,采用高温熔融法制备Ce^(3+)-Tb^(3+)共掺杂黄磷炉渣发光微晶玻璃,通过差热分析(DTA)、X射线衍射(XRD)、稳态/瞬态荧光(FLS)、CIE色度等探究不同的Tb^(3+)掺杂量对微晶玻璃析出晶相、发光性能和样品色度的影响。结果表明,Ce^(3+)和Tb^(3+)的引入,微晶玻璃主晶相为硅灰石,在310 nm波长激发下,随着Tb^(3+)掺杂量增加,位于380 nm处Ce^(3+)的特征发射峰减小,543 nm处Tb^(3+)的特征发射峰增强,证实Ce^(3+)和Tb^(3+)之间存在能量传递,能量传递效率达到24.55%。此外,通过调整Tb^(3+)掺杂量,微晶玻璃发光颜色可由蓝光调至绿光,从而实现发光颜色的可控化。

2.0-μm emission and energy transfer of Ho^(3+)/Yb^(3+) co-doped LiYF_4 single crystal excited by 980 nm

Ho3＋/yb3＋ co-doped LiYF4 single crystals with various Yb3＋ concentrations and ,-~ 0.98 mol% Ho3＋ concentration are grown by the Bridgman method under the conditions of taking LiF and YF3 as raw materials and a temperature gradient （40 ~C/cm-50 ~C/cm） for the solid-liquid interface. The luminescent performances of the crystals are investigated through emission spectra, infrared transmittance spectrum, emission cross section, and decay curves under excitation by 980 nm. Compared with the Ho3＋ single-doped LiYF4 crystal, the Ho3＋/yb3＋ co-doped tiYf4 single crystal has an obviously enhanced emission band from 1850 nm to 2150 nm observed when excited by a 980-nm diode laser. The energy transfer from Yb3＋ to Ho3＋ and the optimum fluorescence emission around 2.0 p-m of Ho3＋ ions are investigated. The maximum emission cross section of the above sample at 2.0 p.m is calculated to be 1.08 × 10-20 cm2 for the LiYF4 single crystal of 1-mol% Ho3＋ and 6-mo1% Yb3＋ according to the measured absorption spectrum. The high energy transfer efficiency of 88.9% from Yb3＋ to Ho3＋ ion in the sample co-doped by Ho3＋ （1 mol%） and Yb3＋ （8 tool%） demonstrates that the Yb3＋ ions can efficiently sensitize the Ho3＋ ions.

Spectroscopy and Energy Transfer in Yb^(3+) and Tm^(3+) Co-doped Gd_3Ga_5O_(12) Crystal

Yb3＋/Tm3＋ co-doped Gd3Ga5O12 single crystal with a dimension of Φ30mm×20mm was grown successfully by Czochralski method.The absorption spectrum was recorded at room temperature and used to calculate the absorption cross-section.Based on the Judd-Ofelt（J-O） theory,we obtained the three intensity parameters and spectral parameters of this crystal,such as the line strengths,oscillator strengths,radiative probabilities and radiative lifetimes as well as the fluorescent branching ratios.Room temperature fluorescence spectra and luminescence decay curves were recorded.The energy transfer between Yb3＋-Tm3＋ was observed and the mechanism was discussed.The stimulated emission cross-section of the 3F4→3H6 transition was calculated by the Füchtbauer-Ladenburg（F-L） equation.The potential laser gains for this transition were also investigated.This crystal is promising as a tunable infrared laser crystal at 2.0 μm.

溶胶-凝胶法制备Gd_(4)Ga_(2)O_(9):Dy^(3+)白光发射荧光粉及其性能

通过溶胶-凝胶法制备了具有白光发射的Gd_(4)Ga_(2)O_(9):x%Dy^(3+)荧光粉,利用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)、紫外-可见漫反射光谱(UV-Vis DRS)和荧光光谱等对产物的物相结构、形貌、组分和光学性能进行研究,并分析了Dy^(3+)掺杂量对样品的影响。XRD结果表明,所制备的样品为Dy^(3+)掺杂的Gd_(4)Ga_(2)O_(9)单斜晶体和少量Ga_(2)O_(3)杂质相的混合物。紫外-可见漫反射光谱结果表明制备的Dy^(3+)掺杂Gd_(4)Ga_(2)O_(9)晶体是一种光学带隙为5.29 eV的直接带隙半导体。荧光检测结果表明Dy^(3+)掺杂Gd_(4)Ga_(2)O_(9)荧光粉可被属于Gd^(3+)激发带的275 nm紫外光有效激发,并在490 nm和575 nm附近分别发射出属于Dy^(3+)的^(4)F_(9/2)→^(6)H_(15/2)和^(4)F_(9/2)→^(6)H_(13/2)跃迁的蓝色和黄色的强烈光,证实在Gd_(4)Ga_(2)O_(9):Dy^(3+)样品中存在显著的由Gd^(3+)到Dy^(3+)的能量传递发光现象。同时,对其发光机制进行了讨论。样品的发光强度随着Dy^(3+)掺杂量的变化而变化,同时影响着样品的发光颜色,Dy^(3+)掺杂量为1.5%和2%时制备的荧光粉可在紫外光激发下分别发射出CIE色坐标为(0.3362,0.3512)和(0.3381,0.3523)、相关色温为5340 K和5263 K的白色光。研究结果表明Gd_(4)Ga_(2)O_(9):Dy^(3+)是一种潜在的紫外光激发白光发射荧光材料。

快速室温合成IRMOF-3用于检测水中的烯啶虫胺

现代农业的迅速发展离不开农药的大量使用,同时也由于农药分子的结构稳定性与高毒性作用,使其成为环境中的主要有机污染物。本研究采用简便快捷的室温合成方法制备了高荧光效率的IRMOF-3,将其应用于有毒新烟碱类杀虫剂——烯啶虫胺(NIT,nitenpyram)的荧光检测分析。结果表明:制备出的IRMOF-3为纯相晶体材料,具有在427 nm稳定的光致发光性质。IRMOF-3的蓝色荧光可被水环境中的NIT快速淬灭,在诸多干扰物中表现出了良好的选择性和强抗干扰能力。以此建立的荧光分析方法在0~38μmol/L的NIT浓度范围内具有显著相关性,检测限(LOD)低至0.35μmol/L,加标回收实验证明该方法有良好的回收率(95.16%~106.51%)且相对标准偏差(RSD)≤6.68%。对多种表征结果的分析说明荧光检测机理主要为NIT对于激发光的能量竞争吸收,而电子转移所导致的荧光淬灭也是IRMOF-3对NIT的荧光检测机理之一。综上所述,基于荧光分析法IRMOF-3实现了对水环境中NIT的高灵敏度含量检测,为未来NIT类水环境污染检测提供了一种简便可靠的分析方法。

Gd^(3+)/Ce^(3+)对Tb^(3+)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SiO_(2)-B_(2)O_(3)-BaF_(2)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Gd_(2)O_(3)掺量下Tb^(3+)的发光性能,并确定了Gd_(2)O_(3)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Gd^(3+)和Ce^(3+)对Tb^(3+)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;Gd^(3+)和Ce^(3+)对Tb^(3+)的发光都具有敏化作用,且Gd_(2)O_(3)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;Ce_(2)O_(3)掺入玻璃后以Ce^(3+)和Ce^(4+)两种价态共存,在还原气氛下掺入相较于空气气氛下掺入更容易保持Ce^(3+)状态,而且Ce^(3+)对Tb^(3+)的发光具有敏化作用,Ce^(4+)会抑制Tb^(3+)的发光。

新型红色荧光粉Sr_(3)CaNb_(2)O_(9):Sm^(3+),Eu^(3+)的发光特性和能量传递分析

利用高温固相反应法制备一系列单基质荧光粉Sr_(3)CaNb_(2)O_(9):xSm^(3+),yEu^(3+)(x=0.04~0.09,y=0.03~0.15),并对样品的物相形貌、发光性能、能量传递机制和CIE色坐标进行分析。研究表明,Sr_(3)CaNb_(2)O_(9):xSm^(3+)荧光粉在激发波长为407 nm时的浓度淬灭点为x=0.07。在Sr_(3)CaNb_(2)O_(9):0.07Sm^(3+),yEu^(3+)荧光粉中,随着Eu^(3+)掺杂浓度的增加,Sm^(3+)的发光强度降低而Eu^(3+)发光强度却先增加后降低,Eu^(3+)的浓度淬灭点为y=0.09。Sm^(3+)→Eu^(3+)的能量传递以电偶极-电偶极相互作用为主,能量传递效率达到76.6%。色坐标图表明Eu^(3+)离子的加入可使色坐标从橙红色区域向纯红色区域移动。此外,样品还具有较高的色纯度和较低的色温。结果表明,Sr_(3)CaNb_(2)O_(9)∶Sm^(3+),Eu^(3+)荧光粉有望成为白光LED发出红光物质的候选材料。

Nd^(3+)/Yb^(3+)掺杂YNbO_4粉末上转换发光特性

采用高温固相法,以50Nb_2O_5-40Y2O_3-2Nd2O_3-8Yb_2O_3的量比在1 300℃下制备Nd^(3+)/Yb^(3+)掺杂YNbO_4粉末样品。运用Judd-Ofelt理论研究样品光谱特性。由吸收谱中各吸收峰面积计算得到谱线强度参数Ωλ(λ=2,4,6),进而得出理论振子强度及实验振子强度,二者均方根偏差δ_(rms)=1.618×10-7。计算了Nd^(3+)能级4F3/2→4IJ'(J'=15/2,13/2,11/2,9/2)跃迁几率、跃迁分支比和能级寿命。4F3/2→4I11/2跃迁分支比最高(56.91%),对应波长1 062 nm。且亚稳态4F3/2能级寿命较长,为1.435 2 ms,适合作为上转换中间能级。在980 nm半导体激光器激发下,观测到波长为487,541,662 nm上转换发光,分别对应于Nd^(3+)的2G9/2→4I9/2、4G7/2→4I9/2和4G7/2→4I13/2辐射跃迁。通过样品上转换发射功率与激光器工作电流进行的曲线拟合,得到吸收光子数目依次为2.06,1.99,2.15,确定3个发射峰均对应于双光子吸收。

Nd^(3+)/Yb^(3+)共掺磷酸盐玻璃光纤的发光与激光特性研究

以970 nm和808 nm半导体激光器作为抽运源,从光纤长度和抽运功率两个方面,探讨了Nd^(3+)/Yb^(3+)摩尔浓度比约为4:1的共掺磷酸盐玻璃光纤的发光与激光特性.在970 nm抽运下,光纤光谱以Yb^(3+)离子的发光为主,但Yb^(3+)→Nd^(3+)能量传递会对光纤光谱(激光和受激放大自发辐射)产生调制作用,调制作用随970 nm抽运功率或光纤长度的增加而显著,甚至出现显著的双波长激光现象.尽管玻璃样品中Nd^(3+)→Yb^(3+)的能量传递效率ηNd→Yb高达64%,但在808 nm抽运下,激光峰始终在1053 nm附近产生,且与808 nm抽运功率大小和光纤长度无关.为解释这一现象,推导了考虑Nd^(3+)离子受激辐射的能量传递模型.从理论模型来看,Nd^(3+)→Yb^(3+)能量传递作用随Nd^(3+)离子受激辐射信号光强度的增加而迅速减弱,这与该光纤实际测试的荧光光谱随808 nm抽运功率的变化规律相符合.因此,当采用Nd^(3+)离子来敏化Yb^(3+)离子时,需要考虑Nd^(3+)离子的受激辐射对Nd^(3+)→Yb^(3+)能量传递的抑制作用.

Energy transfer from Ce^(3+) to Tb^(3+) and Eu^(3+) in zinc phosphate glasses

Ce3+,Eu3+ and Tb3+ singly doped and Ce3+/Eu3+ and Ce3+/Tb3+ co-doped zinc phosphate glasses were prepared by sintering P2O5,ZnO,Ce2(C2O4)3·10H2O and Eu2O3/Tb4O7 mixtures at 1200 °C in the air for 2 h and then annealing at 450 °C for 10 h.The obtained glasses were homogeneous and transparent.The glasses without Ce3+ were colorless and those with Ce3+ showed slightly yellow.The singly doped glasses showed strong emissions and excitations from doped trivalent rare earth ions.Strong energy transfer from Ce3+ to...

Luminescence and Energy Transfer Properties of Ca_2Gd_8(SiO_4)_6O_2∶A(A=Pb^(2+), Tm^(3+))Phosphors

Ca_2Gd_8(SiO_4)_6O_2∶ A(A=Pb^(2+), Tm^(3+))phosphors were prepared through the sol-gel process. X-ray diffraction(XRD), scanning electron microscopy(SEM)and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicate that the phosphors crystallized completely at 1000 ℃. SEM study reveals that the average grain size is 300～1000 nm. In Ca_2Gd_8(SiO_4)_6O_2∶Tm^(3+) phosphors, the Tm^(3+) shows its characteristic blue emission at 456 nm(~1D_2—~3F_4)upon excitation into its ~3H_6—^(1)D_2(361 nm), with an optimum doping concentration of 1mol% of Gd^(3+) in the host lattices. In Ca_2Gd_8(SiO_4)_6O_2∶Pb^(2+), Tm^(3+) phosphors, excitation into the Pb^(2+) at 266 nm(~1S_0—~3P_1)yields the emissions of Gd^(3+) at 311 nm(~6P—~8S)and Tm^(3+) at 367 nm(~1D_2 —~3H_6)and 456 nm(~1D_2—~3F_4), indicating that energy transfer processes of Pb^(2+)—Gd^(3+) and Pb^(2+)—Tm^(3+) have occurred in the host lattices.

Photoluminescence properties and energy transfer in Y_2O_3:Eu^(3+) nanophosphors

The photoluminescence （PL） properties of Y203 ：Eu^3＋ nanophosphors were systematically investigated with the goal of improving the color quality and quantum efficiency of Y2O3 ：Eu^3＋ nanophosphors for potential applications in nano-scale devices. The emission spectra, excitation spectra and fluorescence decay curves were employed to trace the energy transfer process from Eu^3＋ at C3i site to Eu^3＋ at C2 site. The experimental results show that the energy transfer process becomes more and more efficient with the increase in the Eu^3＋ concentration. The emission of Eu^3＋ at C2 site is favorable because it has high radiative efficiency and better color quality. The successful suppress of the emission Eu^3＋ at C3i is especially important for its applications in general illumination or display technology. The quantum efficiency and color quality of Y203 ：Eu^3＋ can be improved by controlling the energy transfer between the Eu^3＋ at S6 site and Eu^3＋ at C2 site.

Tm^(3+)-doped tellurite glass with Yb^(3+) energy sensitized for broadband amplifier at 1400–1700 nm bands

A kind of novel experiment was disclosed as it possessed two bands of fluorescence emission at 1.4 and 1.6 μm, which were perfectly complimentary to the current C band of optic communication. The fluorescence was based on energy transfer and up-conversion processes between Tm^3＋ and Yb^3＋ under direct pumping of 975 nm LD. The spectra and lifetimes of Tm^3＋ fluorescence in the tellurite glass were described. The corresponding fluorescence characteristics and energy migration process were analyzed by the method of lifetime and intensity comparison. The mechanism of the up-conversion based IR fluorescence was presented upon analyzing the multi-photon pumping process. The potential advantages of Tm^3＋/Yb^3＋ co-doped tellurite glass as amplifier material were concluded.

Photoluminescence Properties and Energy Transfer from Ce^(3+) to Tb^(3+) in Zn_2SiO-_4 Host

Zn2Si O4︰Tb^3＋, Zn2 Si O4︰Ce^3＋, Zn2 Si O4︰Tb^3＋, Ce^3＋ phosphors were prepared by solidstate reaction at 1 150 ℃ for 2h under a weak reducing atmosphere. Moreover, the XRD patterns and photoluminescence spectra were recorded and the effects of Tb3＋ and Ce3＋ concentration on the luminescent properties of as-synthesized phosphors were investigated. The emission spectra under ultraviolet light（333 nm） radiation showed a dominant peak at 542 nm attributed to the 5D4→7F5 transition of Tb^3＋, which was enhanced significantly（about 45 times） by the co-doping of Ce^3＋, indicating that there occurred an efficient energy transfer from Ce^3＋ to Tb^3＋. According to the Dexter＇s energy transfer formula of multipolar interaction, it was demonstrated that the energy transfer between Ce3＋ and Tb3＋ was due to the electric dipolar-dipolar interaction of the resonance transfer.

Screening and identification of bioactive compounds from citrus against non-structural protein 3 protease of hepatitis C virus genotype 3a by fluorescence resonance energy transfer assay and mass spectrometry

BACKGROUND Hepatitis C virus genotype 3a(HCV G3a)is highly prevalent in Pakistan.Due to the elevated cost of available Food and Drug Administration-approved drugs against HCV,medicinal natural products of potent antiviral activity should be screened for the cost-effective treatment of the disease.Furthermore,from natural products,active compounds against vital HCV proteins like non-structural protein 3(NS3)protease could be identified to prevent viral proliferation in the host.AIM To develop cost-effective HCV genotype 3a NS3 protease inhibitors from citrus fruit extracts.METHODS Full-length NS3 without co-factor non-structural protein 4A(NS4A)and codon optimized NS3 protease in fusion with NS4A were expressed in Escherichia coli.The expressed protein was purified by metal ion affinity chromatography and gel filtration.Citrus fruit extracts were screened using fluorescence resonance energy transfer(FRET)assay against the protease and polyphenols were identified as potential inhibitors using electrospray ionization-mass spectrometry(MS)/MS technique.Among different polyphenols,highly potent compounds were screened using molecular modeling approaches and consequently the most active compound was further evaluated against HCV NS4A-NS3 protease domain using FRET assay.RESULTS NS4A fused with NS3 protease domain gene was overexpressed and the purified protein yield was high in comparison to the lower yield of the full-length NS3 protein.Furthermore,in enzyme kinetic studies,NS4A fused with NS3 protease proved to be functionally active compared to full-length NS3.So it was concluded that co-factor NS4A fusion is essential for the purification of functionally active protease.FRET assay was developed and validated by the half maximal inhibitory concentration(IC50)values of commercially available inhibitors.Screening of citrus fruit extracts against the native purified fused NS4A-NS3 protease domain showed that the grapefruit mesocarp extract exhibits the highest percentage inhibition 91%of protease activity.Among the compounds identified by LCMS analysis,hesperidin showed strong binding affinity with the protease catalytic triad having S-score value of-10.98.CONCLUSION Fused NS4A-NS3 protease is functionally more active,which is effectively inhibited by hesperidin from the grapefruit mesocarp extract with an IC50 value of 23.32μmol/L.

Site Selective Excitation and Energy Transfer in LiKGdF_5 Crystal Co-doped with Er^(3+) and Tb (3+)

Crystals of LiKGdF 5∶Er 3+, Tb 3+ grown by the hydrothermal synthesis technique with concentrations of 2% and 0.4% were analysed. By using site selective excitation measured at low temperature, luminescence and excitation spectra from Er 3+ and Tb 3+ ions embedded in LiKGdF 5 were clearly separated. The lifetimes of the emitting levels 4S 3/2 of Er 3+ and 5D 4 of Tb 3+ were also determined. Following the site selective spectroscopy study, the dominant energy transfer process from Tb 3+ to Er 3+ in the crystal was then investigated via transient experiments.

LUMINESCENCE AND ENERGY TRANSFER OF Ce^(3+) AND Dy^(3+) IN LaBO_3

This paper studies photo-,cathodo-and X-ray luminescence of Ce^(3+) and Dy^(3+)mono-doped LABO_3 samples or Ce^(3+),Dy^(3+) codoped LaBO_3 samples and the dependence of Ce^(3+) and Dy^(3+) luminescent intensi- ties on compositions.The results obtained indicate that Ce^(3+) can sensitize well the luminescence of Dy^(3+) un- der UV excitation and quench markedly it under CR and XR excitation.This paper also studies the concen- tration dependence of emission intensity of Dy^(3+) under the excitation of peak wavelength of 352 nm,con- firming that the mechanism of concentration self-quenching of Dy^(3+) is a dipole-dipole interaction and the mechanism of the energy transfer from Ce^(3+) to Dy^(3+) is a resonant transfer in which electric multipole interaction plays a leading role.