稀土蓝色光致发光材料研究进展

以稀土蓝色光致发光材料为内容,按照用途分别从灯用三基色荧光粉、PDP显示荧光粉、长余辉发光材料以及上转换发光材料入手,结合使用条件特点分别对其研究进展进行综述,并简要介绍了稀土光致发光材料的改性与组装.     

Eu^3＋在（GdO）3BO3中的发光特性

研究了紫外光（ＵＶ）和阴极射线（ＣＲ）激发下（ＧｄＯ）＿３ＢＯ＿３：Ｅｕ的发光特性及其光谱随组成和结构变化的规律。在这两种激发条件下，（ＧｄＯ）＿３ＰＯ＿３中的Ｅｕ￣（３＋）均能发出明亮的红色荧光。ＣＲ激发下，在加速电压１０～２０ｋＶ、电流密度１～５μＡ／ｃｍ￣２内，Ｅｕ￣（３＋）的发光亮度与电压或电流密度之间均呈良好的线性关系，并具有耐电子束轰击的能力。根据３９５ｎｍＵＶ激发下（Ｇｄ＿（１－ｘ）ＥｕｘＯ）＿３ＢＯ＿３体系中Ｅｕ￣（３＋）的５Ｄ＿１→￣７Ｆ＿１跃迁（５３５ｎｍ）及￣５Ｄ＿ｏ→￣７Ｆ＿２跃迁（６１１ｎｍ）发射强度与Ｅｕ￣（３＋）浓度的关系，证明其浓度猝灭机理分别为电偶极－电偶极相互作用和交换作用。     

MOCVD法生长Ⅲ—Ⅴ族化合物材料近红外光致发光的测量

本文利用近红外光致发光技术测量了ＭＯＣＶＤ生长的Ⅲ－Ⅴ族化合化物Ｇａ０．５Ｉｎ０．５Ｐ和ＩｎＰ中的深能级发光，研究这些深能级发光对激发强度和温度的依赖关系；讨论了Ｇａ０．５Ｉｎ０．５Ｐ外延层深能级发光的辐射机理和来源，得出了ＩｎＰ外延层的Ｃ带发光的热激活能。     

Synthesis and Characterization of Cerium-Doped Lutetium Aluminum Garnet Phosphors by Nitrate-citrate Sol-Gel Combustion Process

Nanosized cerium-doped lutetium aluminum garnet （LuAG：Ce） phosphors were prepared by nitrate-citrate solgel combustion process using 1：1 ratio of the citrate：nitrate. The prepared LuAG：Ce phosphors were characterized by XRD, TEM, photoluminescence and radioluminescence spectra excited by UV and X-ray, respectively. The purified crystalline phase of LuAG：Ce was obtained at 900 ℃ by directly crystallizing from amorphous materials. The resultant Lu- AG：Ce phosphors were uniform and had good dispersivity with an average particle size of about 30 urn. Both photoluminescence and radioluminescence were well-known Ce^3＋ emissions located in the range of 470 -600 nm consisting of two emission bands because of the transition from the lowest 5d excited state （2D） to the 4f ground state of Ce^3＋, which matched well with the sensitivity curve of the Si-photodiode. There was a little red shift for the emission components from the UV-excited emission spectrum to the X-ray-excited emission spectrum. The fast scintillation decay component of 26 ns satisfies the requirements of fast scintillators.     

Triboluminescence of A New Europate Complex

A new europium (Ⅲ)complex Eu(HFNH)3Phen (HFNH: 4, 4, 5, 5, 6, 6, 6-heptafluoro-l-(2-naphthyl)hexane-1,3-dione ; phen : 1, 10-phenanthroline) was synthesized and its tribolumineseent phenomenon was observed. Photoluminescence and tfiboluminescence spectra were successfidly determined. The most intense tfiboluminescent emission originates from the transition of the central Eu^3 ion from ^5D0 level to ^7F2 level. The tribolunlinescent spectrum is basically similar to that of photoluminescence, which correlates with the disorders of F atoms.     

Photoluminescence Properties of A Series of Novel Copolymers Containing Terbium Complexes

The photoluminescence (PL) properties of a series of tri-block copolymers of 9-vinylcarbazole,methyl methacrylate and terbium-methacrylate complex were investigated. In solution, the PL spectra of the copolymers consist of two emission bands, one in the 340-500 nm region and another in 480 - 600 nm,     

Ca2+、La3+掺杂纳米Y2O3∶Eu3+的超声波制备及光致发光性能

采用超声波作用下的均匀沉淀法制备Ca2 、La3 掺杂的纳米Y2O3∶Eu3 荧光粉.通过正交实验研究掺杂浓度、溶液pH、超声功率、反应时间、干燥温度、煅烧温度等因素对其光致发光(PL)性能的影响,得到制备Ca2 、La3 掺杂纳米Y2O3∶Eu3 的最佳条件.结果表明,超声功率、Eu(NO3)3浓度、尿素体积、氨水浓度、煅烧温度是影响样品PL强度的主要因素.Ca2 、La3 离子单一掺杂效果优于两种元素的复合掺杂,最佳条件下制备的Ca2 、La3 分别掺杂的纳米Y2O3∶Eu3 荧光粉的发光性能均显著优于未掺杂样品.     

稀土光致发光安全涂料的制备

采用稀土元素掺杂的碱土铝酸盐光致发光材料研制丙烯酸乳液型发光涂料。乳液型光致发光涂料通过吸收各种可见光实现自动发光功能,本涂料以天然物质为发光材料,以丙烯酸乳液为基料,配合各种颜料、填料及添加剂而成。讨论了这种涂料的发光机理、发光时间。     

Coprecipilation Reaction Synthesis and Photoluminescence of Rare Earth Phosphate-Vanadate Phosphors

By coprecipitation reaction ,rare earth doped yttrium phosphate-vanadate phosphors were prepared.These phosphors were characterized by XRD,SEM,and photoluminescence under 147 or 254nm excitation.The SEM image shows that the size of the phosphor particles is uniform and less than 1μm.     

Preparation and Characterization of Eu／MCM-41 Mesoporous Composite Material

Nanosized mesoporous molecular sieve MCM-41 was synthesized with tetraethyl orthosilicate (TEOS) as the source of silica and cetyltrimethyl-ammonium bromide (CTAB) as the template. The photoluminescent functional supramolecule Eu(DBM)3phen/MCM-41 between the nanosized MCM-41 and Eu(DBM)3phen was prepared in chloroform, and characterized by XRD, HRTEM, IR and fluorescent spectroscopy.     

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   

Influence of annealing temperature on luminescent properties of Eu~(3+)/V~(5+) co-doped nanocrystalline Gd_2Ti_2O_7 powders

Nanosized Gd2(1-x)Eu2xTi2O7:yV5+ phosphors were prepared via sol-gel method and characterized with X-ray diffraction,Raman spectroscopy,diffuse reflectance spectra and photoluminescence spectra.Their PL properties were investigated as functions of the Eu3+ doping concentration and annealing temperature.The results indicated that the as-prepared samples showed a strong emission of Eu3+ under the irradiation of 303 nm.For Eu3+-doped Gd2Ti2O7,the orange emission at 586 nm was the strongest,which was correspond...     

Luminescent properties of MMgP_2O_7：Eu~（3＋）（M=Ca,Sr,Ba） phosphor

A series of red phosphors Eu3+-doped MMgP2O7(M=Ca,Sr,Ba) were synthesized by solid-state reaction method.X-ray powder diffraction(XRD) analysis confirmed the formation of pure CaMgP2O7,SrMgP2O7 and BaMgP2O7 phase.Photoluminescence spectra of MMgP2O7(M=Ca,Sr,Ba):Eu3+ phosphors showed a strong excitation peak at around 400 nm,which was coupled with the characteristic emission(350-400 nm) from UV light-emitting diode.The CaMgP2O7:Eu3+,SrMgP2O7:Eu3+ and BaMgP2O7:Eu3+ phosphors showed strong emission bands peaking at 612,593 and 587 nm,respectively.Due to the difference of the ion sizes between Ba2+(0.142 nm),Sr2+(0.126 nm),Ca2+(0.112 nm),Mg2+(0.072 nm) and Eu3+(0.107 nm),Eu3+ ions were expected to substitute for different sites in CaMgP2O7,SrMgP2O7 and BaMgP2O7 lattice.     

Photoluminescence properties of M2ZnSi2O7:Eu2+（M=Sr,Ba）

The hardystonite phosphors of Eu2+ activated M2ZnSi2O7(M=Sr,Ba) were synthesized by combustion-assisted method.They were systematically characterized by photoluminescence excitation and emission spectra.The emission spectra of these two phosphors showed that the main emission peaks are at 475 and 503 nm due to 4f65d1→4f7 transition of Eu2+.Both phosphors could be efficiently excited in the wavelength range of 250-425 nm where the near ultraviolet light-emitting diode was well matched.The(x,y) color coordinates were determined with the emission values(x,y)=(0.41,0.21) and(0.16,0.45) for the M2ZnSi2O7:Eu2+(M=Sr,Ba) phosphors.     

作为白光LED用铕掺杂氟化镧红色荧光粉的制备与光谱性能研究

采用水热法制备具有单一相六方晶系的LaF₃:Eu3+纳米荧光粉.通过X射线粉末衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、光致发光光谱(PL)和荧光衰减曲线对LaF₃:Eu3+纳米荧光粉进行表征.LaF₃:Eu3+荧光粉的激发光谱主要由250 nm处的宽带(O2-→Eu3+的电荷转移跃迁)和一些尖峰(Eu3+ f-f跃迁)构成,其中位于近紫外区396 nm处有一较强的激发峰.通过发射光谱探测Eu3+在LaF₃晶体中的局部晶场环境.在298 K下激发光谱和发射光谱可知,在六方晶系的LaF₃纳米晶体中的Eu3+晶格位置从D_4h降至到C_2v,这是由于晶格变化所造成的.在396 nm激发下,观测到较优掺杂浓度为10%的LaF₃:Eu3+荧光粉在591 nm(5D₀→7F₁跃迁)处有强烈的红色发射峰.其发光性能表明,LaF₃:Eu3+红色荧光粉在近紫外发光二极管领域具有潜在的应用价值.      

Effects of Eu3+ and Dy3+ doping or co-doping on optical and structural properties of BaB2Si2O8 phosphor for white LED applications

A series of Eu3+ and Dy3+ doped/co-doped as well as un-doped BaB2Si2O8 phosphors were synthesized via solid state reaction method. The PL result showed typical blue and green emission from Dy3+ and red emission from Eu3+. The f-f transitions involving the lanthanide ions along with dopant site occupancy were discussed thoroughly. Phonon assisted energy transfer process was observed from Eu3+ to Dy3+, which enhanced the emissions of Dy3+. Combinations of the emissions from Eu3+ and Dy3+ showed a possible white to red tuneable emission on the CIE diagram. The white warmth emissions of the phosphor were revealed to be adjustable through designing the dopant concentration and excitation wavelengths. An unusual energy transfer that originated from Eu3+ to Dy3+ was also discovered and the energy transfer mechanism was discussed. Proposed energy transfer mechanism was investigated using luminescence decay lifetime. All the phosphor exhibited efficient excitation in the UV range which matched well with the emissions from Ga N-based LED chips. This presented the Ba B2Si2O8 phosphor as a promising candidate for white LED applications. The effects of doping on the structural properties and the optical band gap of Ba B2Si2O8 phosphor were also discussed in this study.     

Luminescent properties of red phosphors K2Ba（MoO4）2：Eu3＋ for white light emitting diodes

K2Ba(MoO4)2:Eu3+ phosphors were synthesized by solid-state reaction. The emission and excitation spectra of K2 Ba(MoO4)2:Eu3+ phosphors exhibited that the phosphors could be effectively excited by near ultraviolet (394 nm) and blue (465 nm) light, and emitted red light at 616 nm. The influence of Eu3+concentration, sintering temperature and charge compensators (K+, Na+ or Li+ ) on the emission intensity were investigated. The results indicated that concentration quenching of Eu3+ was not observed within 30mol.% Eu 3+, 600 oC was a suitable sintering temperature for preparation of K2 Ba(MoO4)2:Eu3+phosphors, and K+ ions gave the best improvement to enhance the emission intensity. The CIE chromaticity coordinates of K2 Ba(MoO4)2:0.05Eu3+phosphor were calculated to be (0.68, 0.32), and color purity was 97.4%.     

New red phosphor （Y, Gd, Lu）BO3： Eu^3＋ for PDP applications

Highly efficient phosphors under vacuum ultraviolet excitation are still demanded for the development of plasma display panels and Hg-free fluorescent lamps. The phosphors of Eu3+ doped (Y, Gd, Lu)BO3 were synthesized with solid state reaction method and the con-tents of Y3+, Gd3+, and Lu3+ for plasma display panel red phosphor were optimized under vacuum ultraviolet excitation. Two new potential candidates, which were (Y1-S-7TGdSLuT)BO3: Eu3+ (0相似文献   

Photoluminescence Characteristics of Gd2Mo3O9 ： Eu Phosphor Particles by Solid State Reaction Method

Eu^3＋-doped Gd2Mo3O9 was prepared by solid-state reaction method using Na2CO3 as flux and characterized by powder X-ray diffractometry. According to X-ray diffraction, this material belonged to a tetragonal system with space group I41/α. The effects of flux content and sintering temperature on the luminescent properties were investigated with the emission and excitation spectra. The results showed that flux content and sintering temperature had effects on the luminescent properties, the optimized flux content and the best temperature was 3 % and 800 ℃ respectively. The excitation and emission spectra also showed that this phosphor could be effectively excited by C-T band （280 nm）, ultraviolet light 395 nm and blue light 465 nm. The wavelengths at 395 and 465 nm were nicely fitting in with the widely applied output wavelengths of ultraviolet or blue LED chips. Integrated emission intensity of Gd2Mo3O9 ： Eu was twice higher than that of Y2O2S ： Eu^3 ＋ under 395 nm excitation. The Eu^3＋ doped Gd2Mo309 phosphor may be a better candidate in solid-state lighting applications.     

Luminescence studies of MBrCl： Eu2＋ （M=Ca, Sr, Ba）

Europium doped MBrCl (M=Ca, Sr, and Ba) phosphors were prepared by solid state reaction in reductive atmosphere. Photolu-minescence (PL), photostimulated luminescence (PSL) after X-ray irradiation and optical absorption studies of MBrCl:Eu2+ (M=Ca, Sr, and Ba) revealed that: (1) blue light emission, under the excitation of 300 nm, was observed in all these phosphors; (2) the shape of the emission spectra in CaBrCl:Eu2+ could be changed by varying the bromine/chlorine ratio during synthesis, while that in SrBrCl:Eu2+ and BaBrCl:Eu2+ showed no change; and (3) PSL was observed in SrBrCl:Eu2+ and BaBrCI:Eu2+ after X-ray irradiation. Difference absorption spectrum (DAS) in SrBrCl:Eu2+ showed two broad bands centered at about 470 and 570 nm, and DAS in BaBrCI:Eu2+ showed two bands at about 550 and 675 nm, respectively. This enabled the use of He-Ne laser (633 nm) or even semiconductor light-emitting diodes (LED) instead of gas lasers for photostimulation.