单一基质白色荧光粉Ca_9Al(PO_4)_7:Ce~(3+),Dy~(3+)的制备与发光性能

采用高温固相法在还原气氛下合成了Ca9(1-x-y)Al(PO4)7:xCe3+,yDy3+荧光材料,并对其发光特性进行了研究。XRD测试表明所合成样品为纯相Ca9Al(PO4)7晶体。在268 nm紫外光激发下,Ca9Al(PO4)7:Ce3+呈现峰值位于363 nm的宽带发射。在350 nm近紫外光激发下,Ca9Al(PO4)7:Dy3+发射光谱为窄带谱,主峰分别位于483 nm和574 nm,对应Dy3+的4F9/2→6H15/2和4F9/2→6H13/2特征跃迁,呈黄白光发射。荧光光谱表明:Ce3+,Dy3+共掺之后,Ce3+不仅对Dy3+的特征发射有明显的敏化作用,而且通过调节Ce3+和Dy3+的掺杂比例,可实现从黄白光到白光的颜色变化。研究发现:Ca9(1-x-y)Al(PO4)7:xCe3+,yDy3+样品中,掺杂离子的最佳摩尔分数为x=0.02,y=0.02,此时色坐标为(0.306,0.313)。     

Ce3+,Mn2+激活氟磷酸钙的合成及其形成机理

合成了发光效率较高、光衰较小的黄色光致发光材料——Ce3+,Mn2+激活的氟磷酸钙(FAP:Ce3+,Mo2+).研究了各种工艺条件对该材料的发光效率、发光光谱及老化性能的影响.结果表明,最佳的灼烧温度在900℃左右;弱还原气氛或保护气氛有利于得到性能较好的材料;原料的化学剂量比M a/Mp,对材料的发光效率和发光光谱影响不大,但对老化速率影响较大,原料中F量应高于正常化学剂量比近一倍.通过对材料形成过程的热分析(差热分析和热失重分析),发现FAP:Ce3+,Mn2+的形成过程与普通卤粉差异很大,研究表明,FAP:Ce2+,Mn2+的形成主要是由650℃～800℃时发生的气相输运过程而引起的.     

Ca10Li（PO4）7∶Dy3+,Ce3+材料的制备及发光性能

采用高温固相法制备了Ca10Li(PO4)7∶Dy3+发光材料,研究了Dy3+在Ca10Li(PO4)7基质中的发光特性。XRD测量结果表明,烧结温度为1 050℃时所制备的样品为纯相Ca10Li(PO4)7晶体。从激发谱可以看出样品主激发峰位于349 nm(6H15/2→6P7/2),363 nm(6H15/2→6P5/2),385 nm(6H15/2→6M21/2),样品可被UVLED管芯有效激发。发射谱由位于481 nm(蓝)和572 nm(黄)的两个峰组成,对应的能级跃迁为4F9/2→6H15/2、6H13/2。研究了不同Dy3+掺杂浓度对发光强度的影响,当Dy3+的摩尔分数为10%时发光最强。掺入Ce3+作为敏化剂,Ce3+→Dy3+发生共振能量传递,当掺杂量为10%Dy3+、14%Ce3+时,样品发光最强,其强度为单掺10%Dy3+时的13.4倍,发光颜色由黄白变为蓝白。     

Ca_9NaZn(PO_4)_7∶Ce~(3+),Mn~(2+)荧光粉的发光性质及能量传递

采用高温固相还原反应合成了新型单相荧光粉Ca9Na Zn(PO4)7∶Ce3+,Mn2+,并对Ce、Mn单、双掺荧光粉的发光性能和能量传递进行分析。在303 nm紫外光激发下,Ce3+,Mn2+双掺体系发射光谱中位于374 nm和650 nm两处的宽带发射峰分别来自于Ce3+的5d→4f和Mn2+的4T1(4G)→6A1(6S)能级跃迁。在该体系中,发现Ce3+和Mn2+之间存在有效能量传递,使得Mn2+的红光发射强度明显增强,能量传递的临界距离Rc=13.85?(1?=0.1 nm),并被证实属于偶极子-四极子共振能量传递。最终,从CIE色度坐标可以看出,通过对共掺离子浓度相对大小的调节可实现从蓝紫光到红光的颜色调控。     

Na_4Ca_4Al_6Si_9O_(24)∶Ce~(3+),Tb~(3+)荧光粉合成及其能量传递研究（英文）

天然方柱石是一种典型的硅酸盐类的发光矿石,针对天然高发光效率方柱石的生成条件及化学成份,采用高温固相法在1 100℃弱还原气氛下合成了Na4Ca4Al6Si9O24(方柱石),并合成了一系列掺杂Ce3+,Tb3+的荧光粉,对其晶体结构做了讨论。通过分别对单掺Ce3+,Tb3+和共掺Ce3+,Tb3+样品发光性质的研究,发现共掺杂的样品其在545nm处由于Tb3+的5 D+4→7 F5跃迁发光强度远远大于单掺Tb3的样品。最后通过掺杂不同浓度Ce3+样品发光性质的研究,以及其荧光寿命和能量传递机理分析,结果表明随着Ce3+掺杂浓度的变化,样品的Tb3+的5 D7 4→F5跃迁(545nm)发光强度及寿命也随着变化,并发现Ce3+对Tb3+存在能量传递,且当Ce3+和Tb3+的质比为0.02∶0.03时能量传递效率最高。通过色坐标的测量,发现随着Ce3+浓度的改变,样品的发光可在绿色区域进行调节。因此,认为Na4Ca4Al6Si9O24∶Ce3+,Tb3+荧光粉有望成为新型白光LED荧光粉。     

新型Sr_3Y(PO_4)_3∶Ce~(3+),Tb~(3+)绿光荧光粉的制备与发光机理的研究

采用传统的高温固相法合成了一种新型的绿色荧光粉Sr3Y(PO4)3∶Ce3+,Tb3+,利用X射线衍射(XRD)和荧光光谱(PL)对该材料的晶体结构和光学性能进行表征。结果分析表明,制得样品的XRD图谱不含Sr3Y(PO4)3以外的杂峰,稀土掺杂并未改变基质的晶体结构,得到的样品为纯相的磷酸钇锶。从本文实验中明显观察到Sr3Y(PO4)3∶Tb3+的激发光谱和Ce3+的发射光谱在320~390nm有重叠,表明在Sr3Y(PO4)3基质中可存在从Ce3+到Tb3+的能量传递。在紫外光(315nm)激发下该荧光粉发射出了Ce3+的蓝光(320~420nm)和Tb3+的黄绿光(480~500nm)和(530~560nm),当Ce3+的浓度为7%,Tb3+的浓度由1%增大到50%时,通过Ce3+的4f→5d电子跃迁将能量传递到Tb3+,然后发生5 D4→7 Fj电子跃迁,该荧光粉发射光谱可由蓝光逐渐调节为黄绿光。本文绘制了Ce3+,Tb3+的能级和Sr3Y(PO4)3∶Ce3+,Tb3+荧光粉中的能量转移过程示意图,并详细阐述了由Ce3+到Tb3+的能量传递过程。通过对比Ce3+和Tb3+的发光强度以及由Ce3+到Tb3+能量转移效率的相对变化,可以得出,随着掺入的Tb3+浓度不断增加,Tb3+的发射强度(5 D4→7 Fj)和能量转移效率(Ce3+到Tb3+)也在增大,而Ce3+的发射强度却有了明显的下降。当Tb3+的浓度为50%时能量转移效率可高达80%。通过CIE色度图也可以看出,当Tb3+浓度不断增大,样品的色坐标从图中的蓝色区域移动到绿色区域。所以在紫外光激发下,Ce3+和Tb3+共掺Sr3Y(PO4)3可作为一种绿光荧光粉应用在白光LED或LCD背光源上。     

电荷补偿剂增强的Ca_(2.96)Eu_(0.04)(PO_4)_2红色荧光粉

采用高温固相法合成了Li+、Na+、K+和Si4+作为电荷补偿剂的Ca2.96Eu0.04(PO4)2白光LED用红色荧光粉。采用X射线衍射仪、荧光光谱仪对材料的物相和发光性能进行了表征。样品的激发光谱由200~310 nm的电荷迁移带和310~500 nm的锐线光谱组成,其中396 nm的激发强度最大。发射光谱主要由5D0→7F1(593 nm)和5D0→7F2(616 nm)跃迁导致的发射峰构成。掺入Li+、Na+、K+和Si4+可以有效提高Ca2.96Eu0.04(PO4)2荧光粉的发光强度,同时对荧光粉的寿命和色坐标影响不大。荧光粉的色坐标均位于红色区域。     

Ce3+,Mn2+激活氟磷酸钙的发光中心及其相互作用

研究了Ce3+,Mn2+激活的氟磷酸钙(FAP:Ce3+,Mn2+)的发光光谱、激发光谱、漫反射光谱、发光衰减以及顺磁共振谱,首次发现了FAP:Ce3+,Mn2+中Ce3+可以形成两种发光中心;同时也发现在该材料中Mn3+的发光中心与普通卤粉相似,即存在MnⅠ和MnⅡ两种中心;研究表明,由Ce3+中心向Mn2+中心的能量传递具有相当高的效率,传递机制属偶极子-偶极子相互作用;在Ce3+→Mn2+能量传递过程中,MnⅠ中心优先被Ce3+中心敏化。     

LiSrPO_4:Tb~(3+)荧光粉的制备及发光特性

采用高温固相法合成了LiSrPO4:Tb3+发光材料,测定了荧光粉的激发光谱和发射光谱,该荧光粉的激发主峰位于330～390nm,属于4f→4f电子跃迁吸收,与UVLED管芯相匹配。在紫外激发下的发射峰由位于490nm(5D4-7F6)、545nm(5D4-7F5)、585nm(5D4-7F4)、622nm(5D4-7F3)的四组线状峰构成,对应Tb3+的特征跃迁,其中545nm处最强,呈现绿色发光。考察了掺杂离子浓度对样品发光效率的影响,Tb3+的最佳掺杂摩尔分数为9%,分析了其自身浓度猝灭机理,探讨了敏化剂Ce3+离子的加入对荧光粉发光强度的影响。LiSrPO4:Tb3+是一种适用于白光LED的绿色荧光材料。     

Ba3Tb(BO3)3:Ce3+:一种白光LED用绿色荧光粉

采用高温固相法合成了Ba3Tb(BO3)3和Ba3Tb(BO3)3:Ce3+两种绿色荧光粉,并研究了材料的发光性质.Ba3Tb(BO3)2材料呈多峰发射,发射峰位于439,493,547,589和629 nm,分别对应Tb3+的5D3→7F4和5D4→7F1=6,5,4,3跃迁发射,主峰为547 nm;监测547 nm发射峰,所得激发光谱由4f75d1宽带吸收(200-330 nm)和4f4f电子吸收(330-400 nm)组成,主峰为380 nm.以Ce3+激活Ba3Tb(BO3)3,所得Ba3Tb(BO3)3:Ce3+与Ba3Tb(BO3),材料的发射光谱分布相同,但发射强度明显增强,说明Ce3+对Tb3+产生了很好的敏化作用;监测547 nm最强发射峰,所得激发光谱为宽带,主峰位于360 nm.改变H3BO3量,Ba3Tb(BO3)3:Ce3+材料的发射强度随之变化,当H3BO3过量15 wt%时,发射强度最大.上述研究结果表明Ba3Tb(BO3)3:Ce3+是一种很好的适于UV-LED管芯激发的白光LED用绿色荧光粉.     

The relation of early lumen depreciation of halophosphate phosphors to antimonous and manganous ion concentrations

Plaque brightness depreciation of Ca₁₀F₂(PO₄)₆:Sb, Mn phosphors subjected to 185 nm radiation in a nitrogen atmosphere is found to be approximately an inverse linear function of Sb concentration and to be independent of Mn content. When irradiation is carried out in the prescence of as little as 0.2% O₂, depreciation of phosphors containing Mn may be much greater than in a pure N₂ ambient. This appears to be caused by photo-oxidation of Mn on or close to the surface of the phosphor crystal. The results of magnetic susceptibility measurements rule out the likelihood that photo-oxidation of Mn, when it occurs, involves either a redox couple with an electron acceptor in the structure or residual oxygen adhering to the surface. It is shown that both the Sb and Mn emission intensities are reduced in the same proportion following exposure to 185 nm radiation, so that loss of luminous efficiency is probably the result of dissipation of excitation energy prior to absorption by Sb and/or a non-radiative process occurring after absorption by Sb. From diffuse reflectance spectra the following radiation-induced absorptions associated with the presence of Sb are found: two unresolved peaks at 320 and 350 nm and absorption at 254 nm. The relative absorption in each of these regions increases with increasing depreciation.     

5d→4f transition in halosulphate phosphors

The synthesis, X-ray diffraction and photoluminescence characteristics in alkaline halosulphate phosphors, such as KZnSO₄Cl:Ce; KMgSO₄Cl:Ce; NaMgSO₄F:Ce and Na₃SO₄F:Ce is reported in this paper. The Ce³⁺ emission in KMgSO₄Cl:Ce phosphor is maximum and it may be useful for scintillation applications.     

Photoluminescence properties of Ce3＋ and Mn2＋-activated Ba9Sc2Si6O24 phosphor for white light emitting diodes

A single-phased silicate compound (Ba1-xCex)9(Sc1-yMny)2Si6O24 was prepared by solid-state reaction at high temperature. From powder X-ray diffraction (XRD) analysis, the formation of Ba9Sc2Si6O24 with an R3 space group was confirmed. In the photoluminescence spectra under ultraviolet (UV) ray excitation, the Ba9Sc2Si6O24:Ce3+,Mn2+ phosphor emits two distinctive color light bands: a blue one originating from Ce3+and a red one caused by Mn2+. The energy transfer process from Ce3+ to Mn2+ was confirmed, the critical radius as well as the transfer efficiency was calculated, and the energy transfer mechanism was discussed. In addition, the decay-time testing indicates that the energy transfer efficiencies from Ce(1) to Mn2+ and Ce(2) to Mn2+ are different. The emission chromaticity of Ba9Sc2Si6O24:Ce3+,Mn2+ phosphor could be tuned from blue to red by altering the Ce3+/Mn2+ concentration ratio.     

Thermoluminescence characteristics of Na3 SO4 Cl:X (X=Ce,Dy, Mn) phosphor

In the present paper Na₃SO₄Cl:Ce, Na₃SO₄Cl:Dy, Na₃SO₄Cl:Mn, of Na₃SO₄Cl:Ce, Dy and Na₃SO₄Cl:Ce, Mn phosphor were synthesized by the wet chemical method. Thermoluminescence (TL) characteristics of Na₃SO₄Cl:Ce, Na₃SO₄Cl:Dy, Na₃SO₄Cl:Mn, Na₃SO₄Cl:Ce, Dy and Na₃SO₄Cl:Ce, Mn phosphors were studied for 5 Gy γ-ray dose. In TL glow curve, two peaks have been observed at 129°C and 224°C for different concentrations of Ce and Dy, whereas Mn peaks at 212°C. The same host is also tried for Ce, Dy (peaks at 126, 219) and Ce, Mn (248°C). A significant single peak is observed in the case of Na₃SO₄Cl:Mn and Na₃SO₄Cl:Ce, Mn. This may be due to the effect of activators. It is found that intensity tends to be increase with increased concentrations of the activators. The TL glow curves of the phosphors have been recorded and irradiated at a rate of 0.39 kGy h^?1 for 5 Gy γ-rays dose. It is also found that all the phosphors are less sensitive as compared with Thermoluminescence dosimetry-CaSO₄: Dy for the same γ-rays dose. The paper discuses the preliminary TL characteristics and effect of γ-rays on Na₃SO₄Cl:Ce, Na₃SO₄Cl:Dy, Na₃SO₄Cl:Mn, Na₃SO₄Cl:Ce, Dy and Na₃SO₄Cl:Ce, Mn phosphors.     

Mg3Bo3F3:Mn2+, R3+(R=Eu、Sm、Dy)的阴极射线发光

本文研究了具有长余辉发光特性的红色Mg3BO3F3:Mn2+,R3+(R=Eu,Sm,Dy)的阴极射线发光性能,以及R3+离子的掺杂对Mg3BO3F3:Mn2+的发射光谱、色坐标等的影响.     

Ln(BO_3,PO_4)[Ln=La,Y]基质中Ce~(3+)、Tb~(3+)、Gd~(3+)的光谱

研究了硼磷酸镧和硼磷酸钇基质中Ce3 +、Tb3+、Gd3+的发射光谱和激发光谱。结果表明 :La(BO3,PO4 ) :Ce ,Tb体系中加入钆后 ,Ce3+的发射降低 ,Tb3+的发射增强 ;Y(BO3,PO4 ) :Ce ,Tb体系中加入钆后 ,Ce3+和Tb3 +的发射均增强 ,且前者增加的幅度高于后者。因此在La(BO3,PO4 ) :Ce ,Tb ,Gd体系中Gd3+离子起着能量传递中间体和敏化剂的作用 ;在Y(BO3,PO4 ) :Ce,Tb ,Gd体系中Gd3 +离子只起敏化剂作用 ,并且阻碍Ce3+→Tb3+的能量传递。与Y(BO3,PO4 ) :Ce,Tb ,Gd相比 ,La(BO3,PO4 ) :Ce,Tb ,Gd对紫外吸收强 ,2 5 4nm激发下发出的光绿色纯度高 ,强度大 ,更适合做荧光灯中的绿粉     

Ln（BO3,PO4）[Ln=La,Y]基质中Ce^3＋、Tb^3＋、Gd^3＋的光谱

研究了硼磷酸镧和硼磷酸钇基质中Ce^3 、Tb^3 、Gd^3 的发射光谱和激发光谱。结果表明：La(BO3,PO4):Ce,Tb体系中加入钆后,Ce^3 的 发射降低,Tb^3 的发射增强,Y（BO3,PO4）：Ce,Tb体系中加入钆后,Ce^3 和Tb^3 的发射均增强,且前者增加的幅度高于后者。因此在La(BO3,PO4):Ce,Tb,Gd体系中Gd^3 离子起着能量传递中间体和敏化剂的作用;在Y（BO3,PO4）：Ce,Tb,Gd体系中Gd^3 离子只起敏化剂作用,并且阻碍Ce^3 →Tb^3 的能量传递。与Y（BO3,PO4）：Ce,Tb,Gd相比,La(BO3,PO4):Ce,Tb,Gd对紫外吸收强,254nm激发下发出的光绿色纯度,强度大,更适合做荧光灯中的绿粉。     

Luminescence of KCaSO4Cl:X, Y (X=Eu or Ce; Y=Dy or Mn) halosulfate material

Polycrystalline KCaSO₄Cl:Eu, Dy, KCaSO₄Cl:Ce, Dy and KCaSO₄Cl:Ce, Mn phosphors prepared by a solid state diffusion method have been studied for its photoluminescence (PL) characteristics. The presence of two overlapping bands at around 400 and 450 nm in the PL emission spectra of the phosphor suggests the presence of Eu²⁺ in the host compound occupying two different lattice sites. The effects of co-doping on the photoluminescence (PL) characteristics of KCaSO₄Cl:Eu or Ce phosphors have been studied. The decrease in peak intensity of the phosphor on co-doping it with Dy gives an insight into the emission mechanism of the phosphors, which involves energy transfer from Eu²⁺→Dy³⁺, Ce³⁺→Dy³⁺ and Ce³⁺→Mn²⁺.     

Ba2MgSi2O7:RE荧光粉发光性能的研究

采用高温固相法合成了Ba2MgSi2O7:RE(RE=Eu2 ,Ce3 ,Tb3 )系列荧光粉,研究了其结构和光谱特性.样品的XRD衍射图表明稀土离子的掺入没有引起基质晶格结构的变化.样品Ba2MgSi2O7:Ce3 在紫外光激发下呈蓝紫色发射,而样品Ba2MgSi2O7:Eu2 在紫外光激发下呈绿色发射.对样品Ba2MgSi2O7:Eu2 的光谱分析表明Eu2 在焦硅酸钡体系中可能占据两个不同格位.此外还分析了Ce3 ,Eu2 和Ce3 ,Tb3 共激活焦硅酸钡盐在紫外光激发下的光谱特性,并对其中存在的能量传递机理进行了讨论.