Preparation and study of red phosphor pewder Gd2-xMo3O9:Eu3+x in white light LED

用高温固相法成功制备了G2-x Mo3O9:Eu3+x,用XRD荧光光谱仪对其物相以及粉体的激发和发射光谱进行表征和研究；结果表明:在395和464nm两主激发峰均可得到616nm处红光发射峰,属于Eu3+典型的5D0-7F2的跃迁所致.由464nm激发得到的发射峰为单峰,峰宽较窄且发射强度较强.     

M1.95P2O7:0.05Eu3+（M=Ba,Sr,Ca）红色荧光粉的制备及其发光性能

以尿素为燃料,采用溶液燃烧法合成出M2P2O7:Eu3+(M=Ba,Sr,Ca)红色荧光粉。利用X射线衍射和荧光光谱研究了激活剂Eu3+对3种荧光粉晶体结构和发光性能的影响。结果表明,制得样品分别为纯相的六方晶系Ba2P2O7、正交晶系Sr2P2O7和四方晶系Ca2P2O7。光谱分析表明,M2P2O7:Eu3+(M=Ba,Sr,Ca)的激发峰位置和发射峰位置均基本相同。M1.95P2O7:0.05Eu3+(M=Ba,Ca)发射红光,其对应于5D0→7F2电偶极跃迁的612nm发射峰强度高于对应于5D0→7F1磁偶极跃迁的588nm和593nm发射峰,说明Eu3+在M2P2O7(M=Ba,Ca)基质中处于非对称格位;而Sr1.95P2O7:0.05Eu3+发射橙红光,Eu3+在Sr2P2O7基质中处于对称格位。在394nm激发下,M1.95P2O7:0.05Eu3+(M=Ba,Sr,Ca)的色度坐标分别为(0.35,0.21)、(0.24,0.15)、(0.35,0.21)。这3种荧光粉均能被394 nm紫外光和464 nm蓝光有效激发,发射红光或橙红光。     

Sr3B2O6∶Dy3+荧光粉的合成与发光性质

采用高温固相法合成了Dy3+掺杂的Sr3B2O6荧光粉,利用XRD、激发发射光谱以及色度坐标图等研究所制备荧光粉的相纯度、发光性能以及色度坐标位置。XRD测试表明在950℃下煅烧6 h制备的样品结构最佳,激发光谱表明在280～480 nm有一系列的激发峰,于350 nm处出现最强的吸收,发射光谱表明在477 nm和573 nm处分别有蓝光发射峰和黄光发射峰两部分,此系列荧光粉发光均呈白色,这种材料有潜力作为全色显示材料应用于三基色荧光灯中。     

Ca3La2(BO3)4:Pr3+荧光粉的制备及其发光性质的研究

通过高温固相法合成了Ca₃La_1.96(BO₃)₄:0.04Pr³⁺荧光粉。通过X射线衍射(XRD)确定了样品的晶体结构，通过激发光谱和发射光谱对样品发光性能进行了研究。X射线衍射测试结果表明，样品已经成相。光谱测试结果表明，在449 nm、473 nm和485 nm光的激发下，样品的发射谱峰位于607 nm附近，这归因于Pr³⁺的¹D₂→³H₄跃迁。监测607 nm时，样品的激发谱由位于320～400 nm的宽激发带和分别位于449 nm、473 nm和485 nm处的窄激发峰组成。位于449 nm、473 nm和485 nm处的激发峰分别归因于Pr³⁺的³H₄→³P₂、³H₄→³P_1...     

Yb3+和Er3+共掺杂的NaY（WO4）2纳米晶的制备与发光性能

采用水热法制备出NaY(WO4):Yb3+,Er3+纳米发光粉。通过X射线衍射、扫描电子显微镜表征了制备的发光粉样品;研究了不同Yb/Er摩尔比对发光强度的影响。结果表明:Yb3+和Er3+共掺杂的NaY(WO4)2属于四方晶系,其粒径在30 nm左右,且分散均匀。当Yb/Er摩尔比为4:1时,NaY(WO4):Yb3+,Er3+发光粉样品的发射峰强度达到了最大值。用980nm激光对其进行激发,在室温下观察到了410、524、553和656nm的发射峰,分别对应于2H9/2→4I15/2,2H11/2→4I15/2,4S3/2→4I15/2和4F9/2→4I15/2的跃迁。根据激发功率与发光强度的关系得出410、524、553和656 nm发射峰均为双光子过程。     

Ba3Y1.9(BO3)4:0.1Sm3+荧光粉的制备及光谱性质的研究

采用高温固相法合成了Ba₃Y_1.9(BO₃)₄:0.1Sm³⁺橙色荧光粉，对其发光性质进行了研究。样品的X射线衍射(XRD)图谱表明制得的样品为纯相。样品的激发光谱由位于200～275 nm之间的宽峰和位于300～500 nm之间的一系列锐峰组成，其中宽峰归因于O^2-→Sm³⁺电荷迁移带跃迁，而锐峰则归因于Sm³⁺的f-f跃迁吸收。在紫外光、近紫外光和可见光激发下，Ba₃Y_1.9(BO₃)₄:0.1Sm³⁺在566 nm、602 nm和651 nm处有强发射峰，分别归因于Sm³⁺的⁴G_5/2→⁶H_J/2(J=5,7,9)特征发射。通过CIE色度图可知样品发光位于橙色区。研究结果表明Ba_3...     

Dy3+掺杂的LiY（MoO4）2发光材料的制备与光谱特性

采用高温固相法在800℃制备了LiY(MoO4)2:Dy3+荧光粉。研究了Dy3+掺杂量、合成温度以及Li+的过量加入对LiY(MoO4)2:Dy3+荧光粉发光强度的影响。结果表明:在紫外光(386nm)激发下,该荧光粉的发射光谱为1个峰值位于488nm和575nm的双峰谱线,其中位于575nm处的黄光发射最强;监测575 nm发射峰得到的激发光谱为主峰位于351、366、386 nm和426 nm的线状谱线。煅烧温度为800℃时合成的荧光粉样品的发光强度达到最大,加入过量的Li+会降低发光强度。随Dy3+掺杂量的增大,荧光粉的发光强度逐渐增强,当Dy3+掺杂量为6%时发射的谱线强度最大。荧光粉的色参数表明,该荧光粉是一种较好的用于白光LED的黄色发光材料。     

柠檬酸凝胶燃烧法制备Nd3+,Yb3+:Y2O3多晶原料及其相组成和荧光特性的研究

本文采用柠檬酸凝胶燃烧法合成了性能优良的Nd3+,Yb3+:Y2O3多晶原料。XRD、IR和SEM测试结果表明样品在900℃煅烧可获得纯相的Nd3+,Yb3+:Y2O3,平均粒径约为40 nm;TG-DTA测试结果表明样品在30～600℃之间失重约为49.28%;从荧光光谱上可以看出两个主要发射峰位于970～1100 nm之间,最强发射峰位于1030nm,对应Yb3+的2F5/2→2F7/2能级跃迁。     

电荷补偿对SrCeO3:Sm3+材料光谱特性的影响

采用溶胶凝胶法合成了SrCeO3:Sm3+,M+(M=Li,Na,K)红色荧光粉,用X射线衍射、荧光光谱表征了样品的物相结构和发光性能。研究了电荷补偿剂对SrCeO3:Sm3+发光性能的影响。结果表明:适量掺入电荷补偿剂没有改变基质的晶型结构。样品的激发光谱由Ce4+→O2–的电荷迁移带和Sm3+的离子特征激发峰组成。样品在波长为408 nm的紫外激发下发射红光,发射主峰为601 nm,对应于Sm3+的4G5/2→6H7/2跃迁。样品的发光强度随电荷补偿剂掺量的增大先增强后减弱;对于不同电荷补偿剂,样品发光强度最大处所对应的电荷补偿剂的掺杂量不同;电荷补偿剂Li+、Na+和K+的最佳掺量分别为5%、2%和0.8%。     

适合近紫外和蓝光激发的Sr2-xZnMoO6:xEu3+红色荧光粉的制备与发光性能

采用高温固相法制备了适合于近紫外、蓝光激发的Sr2–xZnMoO6:xEu3+红色荧光粉。研究了Eu3+掺杂量对样品发光性能的影响。XRD谱显示合成样品为纯相Sr2ZnMoO6晶体。激发光谱由一系列尖峰和电荷迁移带组成,主激发峰位于395nm和465nm处,对应于Eu3+的7F0→5L6和7F0→5D2跃迁。在395nm和466nm激发下,主发射峰分别位于597nm和624nm,对应Eu3+的5D0→7F1和5D0→7F2跃迁。随着Eu3+掺杂量的增加,发射光谱强度先增大后减小,Eu3+最佳掺杂量为0.2。研究了分别以Cl–、Li+、Na+和K+作为电荷补偿剂对发光性能的影响,结果显示Li+补偿效果最为显著。     

Upconversion Luminescence in γ-AlON:Yb3+,Tm3+ Ceramic Phosphors

Upconversion emission properties of γ-AlON:Yb³⁺,Tm³⁺ phosphors were investigated under single-wavelength diode laser excitation of 980 nm. Blue (479 nm) and red (653 nm) emission bands were observed which correspond to the transitions of ¹G₄→³H₆ and ¹G₄→³F₄ of Tm³⁺ ions, respectively. The upconversion spectra show a concentration-dependent luminescence intensity, reaching its peak at a concentration of 1.2 mol% Yb and 0.5 mol% Tm. Pump power dependence of the upconversion emission intensity ( P – I ) revealed that a two-photon process was involved in the blue and red emissions.     

干燥方式对NaY(WO4)2∶Dy3+,Eu3+荧光粉粒度及上转换发光性能的影响

采用水热法合成了Dy3+和Eu3+共掺杂的NaY(WO4)2上转换荧光粉,用XRD, SEM和荧光光谱(PL)等方法对不同干燥方式所得样品的晶体结构、微观形貌、晶粒尺寸及上转换发光性能进行了分析。结果表明,合成样品均为四方白钨矿结构的NaY(WO4)2,空间群为I41/a,掺入Dy3+和Eu3+未改变基质晶格;常规干燥、喷雾干燥、冷冻干燥及真空干燥后荧光粉的尺寸分别为817.91, 486.04, 388.74和349.82 nm,真空干燥的样品分散性最好。在793 nm近红外光激发下,冷冻干燥样品的上转换发光性能最佳,与干燥过程中粉体团聚程度减弱及表面层缺陷减少有关。576 nm处的黄光发射峰来自Dy3+的4F9/2→6H13/2跃迁,595 nm处的橙光、616和655 nm处的红光发射峰分别归属于Eu3+的5D0→7F1, 5D0→7F2和5D0→7F3跃迁。荧光粉的CIE色坐标均位于红光区,表现出良好的红光发射特性,在发光二极管和彩色显示等光电领域具有潜在应用价值。     

Characterization of Ca2SiO4:Eu2+ Phosphors Synthesized by Polymeric Precursor Process

The green emitting Ca₂SiO₄:Eu²⁺ (C₂S:Eu) phosphors were synthesized by the polymeric precursor process (Pechini-type), and the effects of calcination temperature and europium (Eu) doping concentration on the luminescent properties were investigated. The crystalline β-C₂S was obtained in the calcination temperature of 1100°–1400°C, and Eu was reduced into Eu²⁺ by annealing in 5% H₂/N₂ atmosphere. The obtained C₂S:Eu²⁺ phosphors exhibited a strong emission at 504 nm under the excitation of λ_exc=350 nm. The highest photoluminescence (PL) intensity was observed in the C₂S:Eu²⁺ phosphors either calcined at 1300°C or doped with 3 mol% Eu. The obtained PL properties were discussed in terms of crystal structure, particle size and shape, surface roughness, and effect of concentration quenching.     

水热法稀土掺杂LaF3发光材料的制备及其荧光性能研究

稀土掺杂LaF₃发光材料因具有优越的物理与化学性能,已广泛应用于LED显示、照明节能、光学通讯和荧光探针等领域。笔者以氧化镧、氧化铕、硝酸、氟化钠、十六烷基三甲基溴化铵(CTAB)为原料,采用简单水热法合成了LaF₃∶Eu³⁺红色荧光粉,并探讨pH值、反应温度以及表面活性剂用量对产物的物相结构、形貌尺寸和荧光性能的影响。研究结果表明:水热产品均是六方晶系的LaF₃∶Eu³⁺纳米晶,晶粒尺寸介于20~100 nm内。荧光结果表明:LaF₃∶Eu³⁺纳米晶在397 nm(7F0→5L6)光源激发下表现出良好的橙红色发射(592 nm,5D0→7F1)。当Eu^3+离子掺杂摩尔浓度为9%时,样品的荧光强度达到最大值,更高的Eu掺杂浓度会引起荧光猝灭。     

工艺参数对气压烧结制备CaAlSiN3:Eu2+荧光粉性能的影响

采用气压烧结法制备了用于暖白光LED的红色氮化物CaAlSiN_3:Eu~(2+)荧光粉,利用X射线衍射仪(XRD)、扫描电镜(SEM)、荧光光谱仪(PL)对其物相组成、微观形貌、发光性能进行了表征。结果表明:在Eu~(2+)浓度为2mol%、反应温度为1700°C、反应压力为0.65MPa时,急冷温度为1200°C得到的荧光粉结晶最好,发光强度最强。通过改变急冷温度可以使发射峰波长从637nm红移到646nm,这是一种新的调控荧光粉发射峰的手段。经过酸洗后,荧光粉的发射峰强度可以提高约9.3%。     

Efficient red and broadband near-infrared luminescence in Mn2+/Yb3+-doped phosphate phosphor

In this work, we report a novel phosphor LSPO:Mn²⁺ that exhibits red emission at about 616 nm and pleasant broad near-infrared (NIR) emission at about 800 nm with a full width at half maximum (fwhm) of 112 nm. The structure and spectra show that the doped manganese ions occupy two kinds of Sc sites forming Mn1 and Mn2 emission centers, which are responsible for red and NIR emission, respectively. The XPS and low-temperature fluorescence spectra reveal that both red and NIR emissions come from the Mn²⁺ ions. Besides, NIR luminescence is improved by doping Yb³⁺ in LSPO:Mn²⁺, leading to the broadened NIR emission range (700-1100 nm) and enhanced luminescent thermal stability. Our results suggest that the prepared LSPO:Mn²⁺ and LSPO:Mn²⁺,Yb³⁺ phosphors offer the potential applications as red and NIR components in phosphor-converted white-light-emitting diodes (pc-WLED) and broadband NIR pc-LED. Meanwhile, this work provides a new way to design novel broadband NIR phosphors.     

Synthesis and Luminescence Properties of Y3Al5O（12）：Eu^（3＋） Phosphors under Vacuum Ultraviolet Excitation

采用凝胶–燃烧法合成了掺Eu3＋的Y3Al5O12（YAG：Eu3＋）荧光粉。分别采用X射线衍射（XRD）、扫描电子显微镜（SEM）、发光光谱等测试手段分析了不同温度下煅烧所得粉体的物相、形貌与发光性质。XRD和SEM结果表明：YAG：Eu3＋的最低合成温度为900℃,并且在该反应过程中没有中间相YAP（YAlO3）和YAM（YAl）的产生。1 100℃合成的晶粒尺寸比较均匀,平均粒径在90 nm左右。发光光谱的测试表明：在592 nm监控下的真空紫外激发光谱由峰值位于147、156、169nm和214nm的系列激发带组成,其分别归属于铝酸根的基质吸收以及Y3＋和Eu3＋的电荷迁移带吸收。在147nm激发下YAG：Eu3＋荧光粉最强发射峰位于592nm处,属于Eu3＋的5D0→7F1跃迁。Eu3＋在基质中的最佳掺杂摩尔分数为4%。     

Photoluminescence Characteristics of Energy Transfer Between Eu3+and Bi3+in LiEu1−xBix (WO4)0.5(MoO4)1.5

A series of novel red phosphors LiEu_{1− x} Bi _x (WO₄)_0.5(MoO₄)_1.5 ( x =0, 0.05, 0.10, 0.15, 0.20, 0.30, 0.40, and 0.50) were synthesized by the conventional solid-state reaction method. The spectrum and the crystal structure of the phosphors were characterized by Fluorescence spectrophotometry and X-ray diffraction, respectively. The photoluminescent results show that all samples can be excited efficiently by UV (396 nm) and blue (467 nm) light and that they emit red light at 615 nm with line spectra, which are coupled well with the characteristic emissions from UVLED and blue light-emitting diode (LED), respectively. There is an efficient energy transfer from Bi³⁺ to Eu³⁺ ions, leading to the emission intensity of Eu³⁺ being enhanced by 1.5 times, and even more when Bi³⁺ ions are introduced into LiEu (WO₄)_0.5(MoO₄)_1.5. The introduction of Bi³⁺ ions broadened the excitation band of the phosphor, and the optimum doping concentration is found to be 10 mol% of Bi³⁺.     

Strong Green and Red Upconversion Emission in Er3+-Doped Na1/2Bi1/2TiO3 Ceramics

Upconversion emission properties of Na_1/2Bi_1/2TiO₃:Er³⁺ ceramics prepared by the solid-state reaction method were analyzed as a function of Er³⁺ concentration and incident pump power. Strong green (550 nm) and red (670 nm) emission bands were observed with 980 nm excitation at room temperature. Experimental results showed that the emission bands can be tuned by changing Er³⁺ concentration. Upconversion processes in these samples result from not only a two-photon excited-state absorption process but also a nonradiative energy transfer and cross-relaxation process.     

SrMoO_4：0.05Eu~（3＋）,0.05Gd~（3＋）的制备及发光性能研究

分别采用化学沉淀法、微波法、水热法制备了SrMoO4：0.05Eu3＋,0.05Gd3＋荧光粉,并通过X-射线粉末衍射（XRD）、荧光光谱和扫描电子显微镜（SEM）对其晶体结构、荧光光谱和形貌进行了表征。结果表明：SrMoO4：0.05Eu3＋,0.05Gd3＋的结构属体心四方晶系;其宽激发带由Eu3＋-O2-、Gd3＋-O2-电荷迁移带和Mo6＋-O2-基质吸收峰组成,荧光发光以在616nm处Eu3＋的5 D0→7 F2跃迁引起的红光发光最强;254nm紫外光激发时,化学沉淀法制备SrMoO4：0.05Eu3＋,0.05Gd3＋的发光峰比SrMoO4：0.05Eu3＋的相应发光峰强度增大,这是由于Gd3＋向Eu3＋的能量传递敏化增强了Eu3＋的发光。