CaTiO_3∶Pr~(3 )的合成及发光性质

报道了稀土离子Ｐｒ３＋激活的ＣａＴｉＯ３发光材料的合成方法，ＣａＴｉＯ３∶Ｐｒ３＋位于６１３ｎｍ发射与Ｐｒ３＋离子１Ｄ２３Ｈ４光谱发射相一致。讨论了不同合成条件对ＣａＴｉＯ３∶Ｐｒ３＋发光性质的影响     

H_3BO_3添加量对CaTiO_3∶Pr~(3+)余辉性能的影响

采用高温固相法合成CaTiO3∶Pr3+,并通过掺杂H3BO3改性。研究样品的发射光谱、发光亮度及余辉时间,探讨H3BO3添加量对CaTiO3∶Pr3+发光强度及余辉性能的影响。结果表明,所添加H3BO3的摩尔分数为15%时,CaTiO3∶Pr3+粉末具有最佳的余辉性能。     

红色长余辉发光材料Sr_5Al_2O_7S∶Eu~(2+)的制备及发光性能

以工业铝酸钠溶液制备的氢氧化铝为原料,采用高温固相反应法合成了Sr5Al2O7S∶Eu2+红色长余辉材料。用X射线衍射仪及荧光分光光度计对材料的物相及光谱性能进行了分析,考察稀土掺杂量对样品发光性能的影响。结果表明,在稀土激活剂的掺杂量x(Eu)=6%、硼酸加入量9%、1 200℃烧结8h的条件下合成的样品为Sr5Al2O7S∶Eu2+的纯相,激发光谱位于400～500nm,主发射波长在600nm左右,余辉为桔红色。     

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。     

溶胶—凝胶法制备长余辉发光材料SrAl_2O_4∶Eu~(2 ),Dy~(3 )的研究

用溶胶—凝胶法制备长余辉发光材料 Sr Al2 O4 ∶ Eu2 ,Dy3 ,选用柠檬酸合成前驱体柠檬酸盐 ,确定最佳烧结温度在 12 0 0～ 12 5 0℃范围 ,比一般高温固相法制备该产物降低了 2 0 0℃ ,其产物的发射光谱出现了明显“蓝移”现象。     

新型红色长余辉发光材料Y2O3∶Eu3+,Ca2+,Ti4+的燃烧合成和性能表征

采用燃烧法合成了新型红色长余辉发光材料Y2O3∶Eu3+,Ca2+,Ti4+.用X射线衍射仪表征了其结构;用荧光光谱仪测试了激发、发射光谱;以紫外-可见分光光度计测定分析了样品的反射光谱特征.XRD分析证实为立方相的Y2O3.激发光谱为一紫外区内的宽带谱,中心位于253nm,属于Eu3+-O2-的电荷迁移跃迁;发射光谱峰值位于613 nm,对应于Eu3+的5D0→7F2跃迁发射.由于掺杂离子不等价的取代Y3+,形成了电子陷阱和空穴陷阱,两者的复合作用延缓了余辉的衰减.紫外-可见反射光谱得到的结论与荧光激发光谱的结果一致.该样品在紫外线激发下余辉时间长达90分钟.     

Tb~(3+)掺杂BiPO_4基绿色荧光粉的共沉淀法合成及发光性质

以(NH4)2HPO4为沉淀剂,采用共沉淀法合成Tb3+掺杂BiPO4基绿色荧光粉。通过DTA-TG、XRD、IR等方法对荧光粉的结构、组成进行了表征。结果表明,在室温条件下得到了纯六方相BiPO4∶Tb3+,当退火温度为400℃时,开始出现单斜相,温度升高到600℃以上时晶相转变为纯单斜相BiPO4∶Tb3+。利用激发光谱和发射光谱研究了Tb3+在BiPO4基质中的发光性能,六方相和单斜相BiPO4∶Tb3+样品均可发光,在紫外光377 nm紫外光的激发下测定的六方相和单斜相BiPO4∶Tb3+发射光谱的峰位相同,主要发射峰出现在544 nm处强的5D4→7F5跃迁和490 nm、590 nm、622 nm处弱的5D4→7F6、5D4→7F4、5D4→7F3跃迁。当BiPO4∶Tb3+为单斜相时Tb3+在BiPO4基质中的发光强度明显强于六方相BiPO4∶Tb3+。     

燃烧法合成稀土纳米长余辉发光材料SrO·xAl2O3:Eu2+,Dy3+

应用燃烧法在空气中较低的温度(<900℃)下成功地合成了SrO·xAl2O3∶Eu2+,Dy3+稀土纳米长余辉发光材料,并研究了炉温、反应物中铝锶比、助溶剂和可燃物等对发光材料性能的影响。研究结果表明,反应物置于温度为600℃的高温炉中时燃烧得到的产物性能最好,发光粉的粒径在70nm左右,发射光谱的最大波长在520nm左右。与其它合成方法相比,该方法具有合成温度低、反应时间短,获得的产物疏松、硬度小、粒度小等优点。     

(Zn,Ca) Solid-Solution Behavior and Its Effect on Luminescence Properties in Ca_(1-x)Zn_xTiO_3∶0.002Pr~(3 ) Phosphors

Compared withthe classical sulfides MS∶Eu2 (M=Ca,Sr,Ba)red phosphor and ZnS∶Eu2 greenphosphor,the alkali-earth aluminate phosphors havesuperior blue-green long afterglowproperties,such asblue phosphors CaAl2O4∶(Eu2 ,Nd3 ),green phos-phor SrAl2O4∶(Eu2 …     

InBO_3∶Tb~(3+)荧光粉的合成及其发光性质

硼酸盐体系绿色荧光粉具有发光效率高、光色纯、烧结温度低、合成简便、粒径适中等优点,广泛用于等离子彩色电视机。应用高温固相反应法合成In0.98Tb0.02BO3荧光粉,并研究其中Tb3+的光谱性质及能量传递现象。发现激发光谱中Tb3+在274nm处有一最强4f→5d激发峰,能有效地吸收能量。发射光谱在550nm处有一最强峰,属于Tb3+的5D4→7F的跃迁,发绿光。发射峰高而窄,说明荧光粉In0.98Tb0.02BO3发光强度高,且只有一个峰,说明发光颜色纯,有一定的开发价值。还研究了几种因素对In0.98Tb0.02BO3荧光粉相对亮度的影响并得出了合成In0.98Tb0.02BO3荧光粉的最佳实验条件:焙烧温度1300℃,焙烧时间4h。     

发红光的CaS:Bi荧光粉的合成与光谱性质

采用固相反应法用Bi2O3、CaSO4、碳粉、NH4Cl作原料，经高温灼烧．合成了CaS：Bi红色磷光体。该荧光粉有较长的红色余辉，与CaS：Eu类似，可代替CaS：Eu夜光粉用于制造夜光塑料、夜光涂料、夜光瓷，开发夜光仿玉、夜光红宝石、夜光花瓶等产品。     

Luminescence characteristics of Ca_4YO(BO_3)_3 doped with Bi~(3+),Dy~(3+) and Pr~(3+) ions

The photoluminescence(PL) properties of Ca4YO(BO3)3 doped with Bi3+,Dy3+,and Pr3+ ions were investigated.These compounds were prepared using a typical solid-state reaction.The excitation and emission spectra were measured using a spectrofluorometer.For Ca4YO(BO3)3:Bi3+,the excitation spectrum showed the bands at about 228,309,and 370 nm which correspond to the 1S0→1P1 transition and the 1S0→3P1 transition of Bi3+ ions.The emission band at 390 nm corresponded to the 3P1→1S0 transition of Bi3+ ions.For Ca4YO(BO3)3:Bi3+,Dy3+,energy transfer occurred from Bi3+ to Dy3+ somewhat.In Ca4YO(BO3)3:Bi3+,Dy3+,Pr3+,the excitation band at 367 nm was enhanced obviously due to the energy migration from Bi3+ to Pr3+,which converted efficiently the emission of semiconductor InGaN based light-emitting diode(LED).Therefore,the emission of Dy3+ ions was enhanced due to the energy migration from the process of Bi3+→Pr3+→Dy3+.It resulted in the good color rendering.     

Effect of different dopants on the long lasting phosphorescence behavior of CaTiO_3：Pr~（3＋）

In order to improve the luminescence properties of CaTiO3:Pr3+, a series of CaTiO3:Pr3+, such as CaTi0.97Nb0.03O3:Pr3+, Ca0.8Zn0.2TiO3: Pr3+, Ca0.8Zn0.2Ti0.97Nb0.03O3:Pr3+ and B3+-doped Ca0.8Zn0.2Ti0.97Nb0.03O3: Pr3+ were prepared through conventional solid state reaction method. The results of the photoluminescence excitation and emission spectra showed that all the samples emitted red phosphorescence at 612 nm originating from 1D2 to 3H4 emission of Pr3+ under the 337 nm excitation. When examined by the X-ray diffraction (XRD), all the samples presented a predominant phase of CaTiO3 (JCPDS# 42-423) except Zn2+-doped samples which also revealed another phase of Zn2Ti3O8 (JCPDS# 73-579). The results of the afterglow decay curves showed that co-doping Zn2+ ions, Nb5+ ions or adding a small amount of B3+ into Ca0.8Zn0.2Ti0.97Nb0.03O3:Pr3+ were effective in improving the photoluminescence properties of CaTiO3:Pr3+ phosphor. Thermoluminescence results showed that the trap existing in all the samples was the same as in CaTiO3:Pr3+ and doping singly Nb5+ or Zn2+ hardly changed the trap depth but co-doping Nb5+ and Zn2+ could modify the trapping level from 0.63 to 1.26 eV distinctively. In addition, adding a certain amount of B3+ into CTO-PZN could also deepen the trap depth.     

Growth and optical properties of Pr~(3+):La_2CaB_(10)O_(19) crystal

Pr3+ doped La2CaB10O19 crystal were grown by the top-seeded solution growth(TSSG) method.The absorption spectra,emission spectra and lifetime were measured at room temperature.The J-O parameters(Ωt,t=2,4,6),the radiative transition probabilities AJ,J',oscillator strengths PJ,J',radiative lifetime τ,fluorescence branch ratios βJ and the value of integrated emission cross section have also been calculated.Five main absorption bands,3H4 to 3P1+3P2,3P0,1D2,3F3 + 3F4 and 3F2,were observed in the absorption spect...     

Synthesis and luminescence properties of BaWO4：Pr^3＋ microcrystal

BaWO4:Pr3+ (hereafter BWO:Pr) microcrystals were prepared via a hydrothermal route, and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence excitation and emission spectra. The as-prepared products with different morphologies of egg-shape rod, olive-like, and quasi-sphere were obtained by the addition of the surfactants and chelating agents. The emis-sion spectra of BWO:Pr microcrystals showed the strong red emission (642 nm) assigned to the Pr3+ ions of 3P0→3F2 transition with blue ex-citation (484.6 nm, 3H4→3P0).     

溶胶-凝胶法制备YAG:Ho~(3+),Yb~(3+)纳米晶

以稀土氧化物和硝酸铝为原料,采用溶胶-凝胶法合成了YAG:1%Ho~(3+),1%Yb~(3+)纳米晶,并通过正交试验法确定其干凝胶的合成条件.采用DTA-TG、XRD及TEM对干凝胶的合成过程、纳米晶的晶相组成及形貌进行了研究,表明干凝胶经1 200 ℃煅烧后形成了结晶完全的YAG相,无中间相产生.吸收光谱和上转换发射光谱分析表明,Yb~(3+)在材料的发光过程中具有传递能量的作用,Ho~(3+)在跃迁过程中发射出中心波长为650 nm的红色上转换荧光及540 nm的绿色上转换荧光.     

掺杂Tb~(3 )的Ba_2WO_3F_4荧光体的合成及其发光特性

本文采用固相反应法合成了 Ba2 WO3F4及掺杂 Tb3 的 Ba2 WO3F4荧光体 ,测定其 X射线粉末衍射光谱、激发光谱和发射光谱。所合成的 Ba2 WO3F4荧光体为单斜晶系 ,属 CC空间群 (C4S) ,晶胞参数为 :a=1.15 11nm,b=0 .9382 nm,c=0 .7188nm,β=12 6 .0 5°。探讨了 Ba2 WO3F4及掺杂 Tb3 离子的 Ba2 WO3F4荧光体的发光特性     

Luminescence characteristics of LiCaBO_3:Tb~(3+) phosphor for white LEDs

A novel green phosphor,LiCaBO3:Tb3+,was synthesized by solid state reaction method,its luminescence characteristics were investigated,and the formation of phosphors were confirmed by X-ray powder diffraction(XRD).Its excitation band extended from 220 to 400 nm,which was coupled well with the emission of UV LED(350-410 nm).It exhibited a strong green emission located at 544 nm with chromatic coordination(0.25,0.58).The emission intensities of LiCaBO3:Tb3+ phosphor were influenced by varying Tb3+ concentratio...     

Pr~(3+)-doped Li_2SrSiO_4 red phosphor for white LEDs

Novel red phosphors,Li2Sr1-1.5xSiO4:xPr3+(x=0.002,0.003,0.004,0.005,0.006 and 0.008),were synthesized by conventional solid state reaction and the luminescent properties were investigated.The as-prepared phosphors showed red emission at 610 nm under excitation of blue light at 452 nm,indicating that they were promising candidates for red phosphors in the fabrication of white LEDs via blue LED chips.Their excitation bands at 452,476 and 487 nm were attributed to transitions of 3H4→3P2,3H4→3P1+1I6,3H4→3P0 of Pr3+ ion.The red emissions at 606 and 610 nm were originated from the 3P0-3H6 and 1D2-3H4 transitions of Pr3+.The optimum doping concentration of Pr3+ in Li2Sr1-1.5xSiO4:xPr3+ was determined to be x=0.004.With the concentration of Pr3+ over x=0.004,the fluorescence intensity of Li2Sr1-1.5xSiO4:xPr3+ decreased,indicating the concentration quenching occurred.     

Study on Luminescence Properties of High-Density Phosphors BiTaO_~(3+) and BiTaO_4

Theparticleenergydetectedbymodernaccelera torsisgettinghigherandhigher ,whichrequiresbetterperformanceforscintillators .Thehigherthedensityofscintillators ,thelargeritslinearattenuationcoeffi cient ,whichcanreducethevolumeofthedetectingcrystalsandcomplicatedandhugeequipmentsoutsideit ,thenreducetheequipmentcostofacceleratorsgreatly .Itsdetectingcrystalconsistsofthousandsup onthousandsofcrystalarrays .Currently ,becauseofitsprominentmeritsofhighdensity (thatis 8.2 9g·cm- 3) ,shortradiationleng…