PDP用BaMgAl10O17：Eu蓝粉的表面包覆研究

采用硅酸钠水解法对BaMgAl10O17∶Eu^2＋（BAM）蓝粉进行了表面包覆,通过XRD,TEM和AES等分析手段对包膜荧光粉物相、微观形貌及表面元素进行分析。研究结果表明,BAM蓝粉表面包覆了一层厚薄均匀、表面光滑且致密度高的硅氧化合物无机膜,膜厚约为16-20 nm。BAM蓝粉经包覆处理后,抗热劣化性能得以显著提高,在600℃煅烧1 h后,包膜BAM蓝粉的发光亮度和色坐标分别为91%和0.0609,明显优于未包膜蓝粉的75%和0.0633。     

PDP用BaMgAl10O17∶Eu蓝粉的表面包覆研究

采用硅酸钠水解法对BaMgAl10O17∶Eu2+(BAM)蓝粉进行了表面包覆, 通过XRD, TEM和AES等分析手段对包膜荧光粉物相、微观形貌及表面元素进行分析.研究结果表明, BAM蓝粉表面包覆了一层厚薄均匀、表面光滑且致密度高的硅氧化合物无机膜, 膜厚约为16～20 nm.BAM蓝粉经包覆处理后, 抗热劣化性能得以显著提高, 在600 ℃煅烧1 h后, 包膜BAM蓝粉的发光亮度和色坐标分别为91%和0.0609, 明显优于未包膜蓝粉的75%和0.0633.     

球形La2O3∶Eu纳米晶的制备及其发光特性

近年来纳米材料的发展及纳米材料所具有的特异的光学性质,使得纳米发光材料引起越来越多的关注。La2O3结构简单,易于合成,价格便宜．因此以La2O3为基质的发光材料已有很多报道。Mekittric等研究认为,发光材料的形貌,如颗粒度、形状、结晶性等．是影响发光效率的一个重要因素．球形颗粒可以提高其密堆性．从而能有效地提高产品的发光亮度。     

凝胶-燃烧法合成YAG∶Eu~(3+)纳米荧光材料的结构和发光性能

处于4f6电子组态的Eu3 是一个理想的荧光探针离子,通过它的荧光光谱结构可以探测被取代离子周围的对称性。最近,Eu3 作为荧光探针探测了YVO4纳米晶的表面效应[1]。因此Eu3 离子掺杂的发光材料引起了人们的广泛关注[2~4]。钇铝石榴石Y3Al5O12(YAG)具有优良的物理和化学性能,被广     

凝胶-燃烧法合成YAG∶Eu3+纳米荧光材料的结构和发光性能

Y₃Al₅O₁₂∶Eu nanophosphors were synthesized by a gel combustion method. The structure of phosphors was characterized by XRD and FTIR. YAG phase came to occur when YAG∶Eu precursors were sintered at 800 ℃, although the phase was mainly amorphous. The organic groups pyrolyzed completely and pure YAG phase was obtained in the samples sintered at 900 ℃. In the formation of YAG phase, no intermediate phases such as YAP and YAM were detected. Both ⁵D₀ → ⁷F₁ orange and ⁵D₀ → ⁷F₂ red emission could be observed for all the sintered samples. However, the emission of amorphous samples was greatly different from that of crystalline ones. The former was mainly ⁵D₀→ ⁷F₂ red emission, but the latter was ⁵D₀ → ⁷F₁ orange emission. As sintering temperature rises, the ratio of orange to red for phosphors increases. Eu could be doped up to 8% in YAG host lattice, and fluorescence quenching was absent. It indicated that the gel combustion synthesis method can increase emission intensity and quenching concentration due to a good distribution of Eu³⁺ activators in Y₃Al₅O₁₂ matrix.     

特殊形貌GdF3:Eu3+纳米发光材料的制备及性能

以PEG-2000、柠檬酸和甘氨酸为表面活性剂,采用水热法制备出扁平纳米棒、纳米花和纳米片状的GdF3∶Eu3+发光材料,并对其结构和性能进行了表征.XRD结果表明,所得样品均为正交晶系.FESEM照片表明,使用不同表面活性剂所制备的产物形貌不同.研究了以PEG-2000为表面活性剂时反应物浓度对产物形貌的影响,并对其生长机理进行了探讨.荧光光谱表明,在不同波长激发光的照射下,GdF3∶Eu3+纳米晶的最强发射峰均位于591 nm处,对应于Eu3+的5D0→7F1磁偶极跃迁.GdF3∶Eu3+的Gd3+-Eu3+之间发生了有效的能量传递.不同形貌样品的发光强度不同.     

纳米棒束YPO4:Eu的合成及其发光性能

以硝酸钇、硝酸铕和磷酸二氢铵为反应前躯体,等摩尔的硝酸钠和硝酸钾为反应介质,采用熔盐法合成了YPO<,4>:Eu纳米棒束(1).XRD研究表明,1在300℃开始结晶,450℃结晶完全;SEM,TEM和HR-TEM研究表明,1主要是由结晶度高的纳米棒组成的纳米棒束,尺寸分布均匀,纳米棒束宽50 nm～60 nm,长1 0...     

特殊形貌GdF3:Eu3+纳米发光材料的制备及性能

以PEG-2000、柠檬酸和甘氨酸为表面活性剂,采用水热法制备出扁平纳米棒、纳米花和纳米片状的GdF3:Eu3+发光材料,并对其结构和性能进行了表征.XRD结果表明,所得样品均为正交晶系.FESEM照片表明,使用不同表面活性剂所制备的产物形貌不同.研究了以PEG-2000为表面活性剂时反应物浓度对产物形貌的影响,并对其...     

SrMgB6O11:Eu3+纳米材料的水热法制备及发光性能研究

采用水热法制备了Eu3+掺杂SrMgB6O11纳米发光材料.利用X射线粉末衍射仪(XRD)、场发射扫描电子显微镜(FESEM)和荧光光谱对SrMgB6O11:Eu3+样品进行表征.结果表明:采用水热法可以成功地合成粒度均匀、结晶完好的SrMgB6O11:Eu3+纳米发光粉.深入研究了反应温度和pH值对SrMgB6O11:Eu3+纳米材料的晶体结构及形貌的影响.结果表明,在120℃时形成了尖锐且强度最强的衍射峰,同时FESEM也表明此时所得材料为纳米棒组成的规则扇形形貌,此后随着温度的升高,XRD图中衍射峰的位置和强度发生变化,说明荧光粉的晶体结构发生变化,FESEM也表明该荧光粉已变为球形颗粒.归属了发射光谱和激发光谱中各激发峰所对应的能级跃迁.荧光光谱也显示:反应温度和pH值影响着Eu3+在晶格中的对称性,且反应温度为120℃及pH值为9时,Eu3+在晶格中的对称性较好.另外,还初步探讨了纳米粒子的生长机制.     

(Ce0.67Tb0.33)MgAl11O19和BaMgAl10O17:Eu2+荧光体的微波辐射合成及其发光性能

用微波辐射法合成了(Ce0.67Tb0.33)MgAl11O19(P-G)和BaMgAl10O17(P-B)两种荧光体, 经X射线粉末衍射分析, 其d值和I/I0值与JCPDF36-73和26-163基本一致. 计算得到P-G的晶胞参数a=0.5582 nm, c=2.1884 nm; P-B的晶胞参数a=0.5616 nm, c=2.2614 nm. 测定了两种荧光体的激发光谱和发射光谱. P-G的色坐标x=0.316, y=0.565; P-B的色坐标x=0.156, y=0.106. 与市售同类荧光粉相比, P-G的相对发光强度为88%, P-B的相对发光强度为80%.     

Synthesis and Luminescent Properties of Novel Nanometer-sized ScAlMgO_4：Eu~（3＋） Phosphors for PDP

Novel nanometer-sized ScAlMgO4:Eu3+ phosphors were successfully synthesized by the citric acid complexation method.The mean particle size of the obtained powders was within the range of 100～150 nm according to the SEM patterns.In ScAlMgO4:Eu3+ showed strong characteristic red emission,of which the maximum emission peak was located at 629 nm for ultraviolet(UV) excitation.The dependence of photoluminescence intensity on Eu3+ concentration was also studied in detail,and the emission intensity of Sc1-xEuxAlMgO4 was about 10% at optimized Eu3+ concentration.Furthermore,the luminescence decay measurements showed that the lifetimes of Eu3+ were in the range of millisecond.The obtained ScAlMgO4:Eu3+ phosphors with nanometer size and excellent luminescence efficiency would be potential red phosphors in plasma display panels.     

一种电致发光有机化合物的合成及其发光性能的检验

制备了有机电致发光材料1,3-二[（4′-特丁基苯基）-（1″,3″-噁二唑-5）]-苯（以下简写作OXD-7）,通过核磁共振光谱、红外光谱对其结构进行了表征。利用紫外可见吸收光谱、荧光光谱和循环伏安法等研究了其最高被占用分子轨道（HOMO）及最低空余分子轨道（LUMO）能级及发光性能。OXD-7的HOMO能级为5．24eV,LUMO能级为1．69eV。OXD-7在306nm波长处有一吸收峰。采用300nm的紫外光激发,荧光发射峰值波长为366．6nm。     

异核稀土双亚砜配合物的合成、表征和荧光性质

合成得到一系列异核土双乙烷配合物和异核稀土双乙烷与１,１０－啡咯啉的配合物,通过元素分析,电感耦合等离子体法,电导,红外和紫外光谱对配合进行了表征,并研究了这些配合物的固体和溶液的荧光光谱。     

甘氨酸燃烧合成YAG∶Tb荧光粉的微观结构和发光特性

Luminescent terbium doped yttrium aluminum garnet (YAG∶Tb) powders were prepared using yttrium and aluminum oxide precursor particles produced by combustion process with glycine. Heat treatment of the resulting precursor powders at 950℃ or 1450℃ for 2h, yielded pure YAG particles. The morphology of YAG∶Yb phosphor after sintering at 1450℃ appeared to be spherical or elliptical and the grain size of the phosphor was in the range of 0.6 to 1.4μm. From the photoluminescence spectra, transitions ⁵D₄- ⁷F_J corresponding to Tb³⁺ in YAG matrices were identified. The prominent transition ⁵D₄- ⁷F₆ emission for YAG∶0.05Tb phosphor after sintering at 1450℃ was very significant to improve the chromaticity of YAG∶Tb phosphor.     

Coordination Polymers with Bipyridyl Diene and Triene Ligands: Synthesis,Structures and Luminescent Properties

Solvothermal reactions of cadmium salts with bipyridyl diene and triene ligands[1,3-bis((E)-2-(pyridin-4-yl)vinyl)benzene-(1,3-bpeb) and 1,6-bis(4-pyridyl)-1,3,5-hexatriene(bphte)] and one bipyridyl triene ligand[1,6-bis(4-pyridyl)-1,3,5-hexatriene-(bphte)] in the presence of auxiliary carboxylic acids including 2,6-dichlorobenzoic acid(2,6-HDCBA) and 2-naphthal-enecarboxylic acid(2-HNCA) gave rise to four coordination polymers[Cd(bphte)(2,6-DCBA)₂]_n(1), {[Cd(bphte)(2-NCA)₂]·5.8H₂O}_n(2),[Cd₂(1,3-bpeb)₂(2,6-DCBA)₄]_n(3) and {[Cd₄(1,3-bpeb)₄(2-NCA)₇(HCOO)]·     

Tb掺杂SiO2-B2O3-NaF玻璃的制备及发光性质

使用正硅酸乙酯、硼酸和氟化钠为前驱体,0.10 mol•L-1TbCl3溶液为掺杂剂,通过溶胶-凝胶方法制备了Tb3＋掺杂的SiO2-B2O3-NaF玻璃,研究了Tb3＋在SiO2-B2O3-NaF体系中的发光性质,结果显示发光体能产生强的绿色发光(544 nm),归属于Tb3＋的5D4—7F5电子跃迁.Tb3＋含量不同时,除发光强度不同外,其发射光谱基本相同,并且在低掺杂Tb3＋样品和低退火温度样品中检测到了来自5D3跃迁产生的峰,其跃迁随Tb3＋掺杂浓度的增加和退火温度的升高而发生猝灭,这种现象归因于5D3－5D47F6—7F0和/或5D3—7F07F6—5D4跃迁中发生了交叉弛豫现象.Tb3＋在SiO2-B2O3-NaF玻璃中的激发光谱由一个宽峰和一系列窄峰组成,宽峰最大波长位于230 nm,对应于Tb3＋的4f 8—4f 75d 1跃迁,一系列窄峰位于300～380 nm处,归属于4f 8跃迁,所有发光材料的XRD和TEM测试显示材料是非晶态的.     

若干物理处理方法对稀土荧光粉Y2O3:Eu3+发光性能的影响

采用物理法对商品化稀土荧光粉Y2O3：Eu^3＋进行改性，考察了真空干燥温度、焙烧温度对其发光性能的影响。SEM和TEM观测结果表明，经过200℃真空干燥后，随着焙烧温度的增加，荧光粉的分散性得到改善，且以纳米颗粒为主（5～85nm）。XRD测量结果表明，随着焙烧温度的增加，Y203：Eu^3＋的结晶度逐渐增加。发射光谱测试结果表明，真空干燥温度为200℃，焙烧温度为1200℃时得到的样品的发光性能较好。     

Theoretical Investigation on the Luminescent Properties of Polyfluorene and Poly（fluorene-co-thiophene）

The density functional theory was employed to study the structures, ionization potentials(IPs), electron affinities(EAs), and HOMO-LUMO gaps(ΔH-L) of the oligomers. The time-dependent density functional theory(TD-DFT) and ZINDO were employed to study the lowest excitation energies(Egs) and the absorption and emission spectra of the oligomers of polyfluorene(PF) and poly(fluorene-co-thiophene)(PFT). By extrapolating ΔH-L and Egs to those of infinite chain length, band gaps and effective conjugation lengths o...     

形貌可控的LaPO4:Eu3+荧光粉的制备与发光性能研究

分别以硝酸镧、多聚磷酸和磷酸二氢钠为原料,在无任何添加剂和模板的条件下,采用水热法分别合成微纳米球和纳米棒两种形貌的磷酸镧.通过场发射-扫描电子显微镜(FE-SEM),X射线衍射(XRD),红外光谱(FTIR)和荧光光谱(PL)等测试手段对以上不同形貌的样品的相结构以及微观形貌进行表征.FE-SEM测试结果表明:当以多聚磷酸为磷源时,在酸性条件下可以得到平均粒径约为2μm左右的磷酸镧微球;而当以磷酸二氢钠磷源时,在酸性条件下则可以得到纳米棒;两者的分散性良好.XRD测试结果表明:两种不同形貌的样品均为单斜晶系结构.荧光光谱分析可知:Eu3+的掺杂浓度相同时,球状样品的发光强度远大于棒状样品.     

Hydrothermal Synthesis and Luminescent Properties of Flowerlike Zn2GeO4 and Mn2+-Doped Zn2GeO4 Hierarchical Architectures

Three-dimensional(3D) flowerlike hierarchical Zn₂GeO₄ and Mn²⁺-doped Zn₂GeO₄ microstructures have been prepared by a facile hydrothermal approach. X-Ray diffraction(XRD), field emission scanning electron microscopy(FESEM), transmission electron microscopy(TEM) and photoluminescence(PL) spectrometry were employed to characterize the samples. Such flowerlike hierarchical Zn₂GeO₄ microstructures with an average diameter of 3―4 μm were found to be constructed by abundant single crystalline nanorods of about 90 nm in diameter. The luminescent properties of Zn₂GeO₄:xMn phosphors with different contents of Mn²⁺ as an activator were investigated. The Mn²⁺-doped samples showed green luminescence corresponding to the d-d transition of Mn²⁺ under the irradiation of UV light. The red shift(from 531 nm to 538 nm) in λ_em with increasing Mn²⁺ content was observed in the luminescent spectra, which should be attributed to a weak crystal field because of the substitution of Zn²⁺ by Mn²⁺ at a distorted tetrahedral lattice site.