共查询到20条相似文献,搜索用时 15 毫秒
1.
用沉淀法合成了Y10W2O21:Eu纳米发光材料,利用X射线衍射谱(XRD)和场发射扫描电镜(FE-SEM),对样品的结构和形貌进行了表征.测量了各样品的激发光谱、发射光谱,绘制了Eu3+发光的浓度猝灭图,计算了各样品的部分J-O参数和EC+5 D0能级量子效率,对Eu3+掺杂的Y10W2O21纳米发光材料的光致发光性... 相似文献
2.
研究了退火温度对ZrO2纳米材料中Eu3+离子发光性质的影响.材料的结构、晶粒尺寸和形状以及晶格的排列分别由XRD,TEM表征.结果表明:用共沉淀法制备的ZrO2纳米材料具有不随退火温度变化、稳定的四方结构;材料的晶粒尺寸随退火温度的提高而增大;品格的排列由无序逐渐变为有序;发射光谱表明其主要发射在595 nm和604 nm处;在394 nm的紫外光辐照下得到了不同样品的604 nm荧光发射强度的变化不同.这种现象与样品中O2-离子含量和样品表面的表面缺陷有关;另外,电荷迁移带随退火温度的变化而变化. 相似文献
3.
4.
采用化学共沉淀法一次煅烧工艺合成了BaAl2Si2O8:Eu2+蓝色荧光粉.用X射线衍射仪和荧光分光光度计等对BaAl2Si2O8:Eu2+蓝色荧光粉的相结构、发光性能进行了测试.结果表明:化学共沉淀法一次煅烧工艺合成的BaAl2Si2O8:Eu2+蓝色荧光粉为单相;其激发光谱分布在240-410 nm的波长范围,峰值位于320 nm处,可以被InGaN管芯产生的350-410 nm辐射有效激发;在365 nm近紫外光的激发下,测得其发射光谱是位于465 nm附近的宽带峰.BaAl2Si2O8:Eu2+蓝色荧光粉的发光强度随Eu2+浓度的增大逐渐加强,当Eu2+掺杂的摩尔分数为3.5%时,发光强度达到最大值,而后随掺杂浓度的增加而减小,发生浓度猝灭;根据Dexter能量共振理论,该浓度猝灭是由于Eu2+的离子间交换相互作用引起的. 相似文献
5.
6.
The photoluminescence (PL) property of Y2MoO6:Eu3+ doped with Li+ is investigated in this paper. The red luminescence of Eu3+ in Y2MoO6 lattice has greatly enhanced by codoping monovalent alkali metal ions Li+ into the lattice. The drastic increase in the luminescence intensity of Y2?xLixMoO6:Eu3+ originates from the reason that the Li+ ions may serve as a self-promoter for better crystallization to reduce the defect or as a lubricant for the complete incorporation of the Eu3+ ions into the Y2MoO6 host. 相似文献
7.
Ru-Yuan Yang Min Hang Weng Huang-Yu Chen Chin-Min Hsiung Shin-Hung Chen 《Journal of luminescence》2012,132(2):478-483
This paper describes an investigation of the crystalline morphology and photoluminescent properties of YInGe2O7 powders doped with different Eu3+ concentrations using microwave assisted sintering and conventional sintering. X-ray powder diffraction analysis confirmed the formation of monoclinic YInGe2O7 structure as YInGe2O7:Eu3+ powders were sintered at 1200 °C in microwave furnace for 1 h, and the raw material phase of Y2O3 was observed when Eu3+ concentration was below 30 mol%. Scanning electron microscopy showed microwave assisted sintering results in smaller particle size and more uniform grain size distribution. In the photoluminescent (PL) studies, the concentration quenching effect was observed under the excitation at 393 nm, but not under the excitation at CTS band. The 5D0→7F2 transition (620 nm), exhibits a non-exponential decay behavior as YInGe2O7:Eu3+ powders were sintered by microwave with the Eu3+ concentration higher than 50 mol%. 相似文献
8.
以甘氨酸为燃料,采用溶液燃烧法制备了Y2O3:Eu3 (3%)纳米粉末,并研究了制备过程中前驱溶液的pH值对Y2O3:Eu3 发光性质的影响.从XRD和SEM分析得到,随着溶液pH值的增大,样品颗粒逐渐变大,并且多孔粉末变得越来越致密.通过对样品发光性质的测量得到,随着pH值的增大,样品发光逐渐增强,但寿命逐渐变短.激发谱显示,基质吸收和电荷迁移带的相对强度比随着pH值的增大逐渐减小. 相似文献
9.
Kavita Mishra Y. Dwivedi A. Rai S. B. Rai 《Applied physics. B, Lasers and optics》2012,109(4):663-669
Detailed structural and spectroscopic characterizations of Pr:Y2O3 nanophosphor have been carried out. On ultraviolet light (at 266?nm) excitation, intense red emission along with weak emissions in blue, green and infrared regions have been observed. The phenomena for the observed emission have been thoroughly explained in the present work and it was finally concluded that the?direct excitation through low-lying 4f15d band of Pr3+ ions and through the conduction band of Y2O3 nanophosphor are the main channels for the observed emissions. The calculated quantum efficiency (QE) for the red emission is found to be ~80?% while the CIE coordinates are (0.65, 0.34) quite close to the standard values. These studies clearly indicate that Pr:Y2O3 nanophosphors are promising and futuristic red luminescent material for the development of various display devices and UV detectors. Time resolved spectroscopy has been further used to investigate luminescence dynamics. 相似文献
10.
通过分析影响Y2O3: Eu3+在488nm激光激发下的5D0→7F2变温荧光发射强度的因素,建立起公式并对实验数据进行拟合,得到纳米晶的温度猝灭速率大于体材料的温度猝灭速率.测得Y2O3: Eu3+纳米晶和体材料的5D0→7F2发射峰的变温线宽,通过内应力和量子限域效应对其不同进行了解释.测量了Y2O3: Eu3+在共振激发下的5D0能级的荧光衰减时间随温度的变化,又利用公式对其进行拟合,得出了相比于体材料,纳米晶的辐射跃迁速率和无辐射跃迁速率均增大,但量子效率变小的结论.然后利用晶格畸变和表面态效应对上述结论进行了解释. 相似文献
11.
Ru-Yuan Yang Huang-Yu Chen Shoou-Jinn Chang Yu-Kai Yang 《Journal of luminescence》2012,132(3):780-783
In this paper, effect of Eu3+ doping concentrations on microstructure and photoluminescence of Sr2SiO4 phosphors was investigated. The Sr2?xSiO4:xEu3+ phosphors with x=0.05, 0.1, 0.2, 0.3 were synthesized by microwave assisted sintering at 1200 °C for 60 min in air. X-ray powder diffraction analysis confirmed the formation of pure Sr2SiO4 phase without second phase or phases of starting materials irrespective of the adding amount of Eu3+. From scanning electron microscopy image, it is found that with more Eu3+ ions introduced to Sr2SiO4, the shape of the particles is not much different from each other, but the particle size decreases significantly from 1 to 2 μm (when x=0.05) to less than 500 nm (when x=0.3). The emission spectrum was located obviously at 617 nm as the excitation spectrum at λex=395 nm, and it had best emission intensity when x=0.1. 相似文献
12.
Ping Huang Dan Liu Cai E. Cui Lei Wang Guowei Jiang 《Applied Physics A: Materials Science & Processing》2014,116(2):759-765
Red long-lasting phosphor Y2O2S:Eu3+, Zn2+, Ti4+ nanotubes were prepared by hydrothermal method. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence and thermoluminescence spectra (TL) were used to characterize the long-lasting phosphor. XRD investigation revealed that the product synthesised under 750 °C for 6 h was a pure phase of Y2O2S. SEM observation showed that the sulfuretted phosphor inherited the tube-like shape from the precursor. Under 325 nm UV excitation, the result indicated the strongest red-emission lines at 627 nm, corresponded to the transition from 5D0 to 7F2 level of Eu3+ ion. Both the afterglow decay curves and TL curves revealed that the phosphor had efficient luminescent and excellent long-lasting properties. 相似文献
13.
Abstract Luminescence spectra from Eu3+ ion in C-type Eu2O3 under high pressures have been obtained. The spectral shifts can be used to study the effect of pressure on the spin-orbit and the Coulomb interactions of the 4f electrons, which are correlated with expansion of the 4f-electron wave functions. This expansion with the application of pressure results in both the variation of the electronegativity and radius of the Eu3+ ion and, ultimately, the phase transformation from C-to B-type Eu2O3. Therefore, core 4f-electrons can thus be thought of as quasivalence electrons. 相似文献
14.
采用化学共沉淀法一次煅烧工艺合成了BaAl2Si2O8:Eu2+蓝色荧光粉.用X射线衍射仪、荧光分光光度计和扫描电镜测试了助熔剂H3BO3对BaAl2Si2O8:Eu2+蓝色荧光粉物相结构、发光性能、形貌等的影响.研究表明:化学共沉淀法一次煅烧工艺合成的BaAl2Si2O8:Eu2+蓝色荧光粉为单相,H3BO3的加入使基质结构由六方相转变成单斜相,并引起发射主峰位置和发射强度的变化;BaAl2Si2O8:Eu2+蓝色荧光粉的发光强度随着H3BO3加入量的增加先增强,后减弱,当加入H3BO3的质量分数为1.5%时,发光强度最大;H3BO3的加入使合成BaAl2Si2O8:Eu2+蓝色荧光粉的颗粒呈类球形,分布更加均匀,粒度更小.
关键词:
3BO3')" href="#">H3BO3
2Si2O8:Eu2+')" href="#">BaAl2Si2O8:Eu2+
发光特性
化学共沉淀法 相似文献
15.
Aradhana Jyotsana Gulab Singh Maurya Anoop K. Srivastava Awadhesh K. Rai B. K. Ghosh 《Applied Physics A: Materials Science & Processing》2014,117(3):1269-1274
Yttrium oxide (Y2O3) doped with Dy3+ & Eu3+ nanoparticle has been synthesized by solution combustion method. The formation of the compounds has been checked by X-ray diffraction method. The crystallite/particle size has been measured using Scherrer formula as well as by transmission electron microscopy which show that the size of the particles are in the nanorange. The frequency and temperature dependent variation of impedance Z*, dielectric constant (ε′), dielectric loss (ε″) and AC conductivity (σ) of Y2O3: Dy3+ & Eu3+ nanoparticles were also measured. The real and imaginary part of complex impedance makes semicircle in the complex plane. The center of semicircle arc is found to be shifted toward higher value of real part of impedance with increasing temperature. This indicates that the conductivity of the material increases with the increase in temperature. Cole–Cole plots demonstrate that the dielectric relaxation process occurs in the material. The AC conductivity (σ AC) increases with the increase in temperature within the frequency range of 103–107 Hz confirming the hopping of the electrons in the conduction process. The value of impedance decreases sharply with increasing frequency and attains minimum value after 105 Hz at all temperatures. 相似文献
16.
17.
采用燃烧法制备了不同尺寸的Er3+掺杂Y2O3粉体材料,研究了尺寸效应对Er3+掺杂纳米Y2O3材料发光特性的影响.光声光谱显示,对于不同晶粒尺寸的样品,Er3+离子光声峰位置几乎保持不变.这表明小尺寸效应对稀土离子能级位置影响很小.对488 nm激光激发下的发射谱的分析发现,随着样品颗粒尺寸的减小,4S3/2能级和2H11/2能级向基态发射的强度比减小.分析认为属于超敏跃迁的2H11/2能级向基态的荧光发射随粒子尺寸的减小而相对增强.对518 nm激发下554 nm的荧光衰减曲线的测试和分析发现,处于4S3/2激发态的Er3+离子对之间的上转换能量传递概率随粒子尺寸的减小而增加. 相似文献
18.
Timur Sh. Atabaev Hong-Ha Thi Vu Yang-Do Kim Jae-Ho Lee Hyung-Kook Kim Yoon-Hwae Hwang 《Journal of Physics and Chemistry of Solids》2012,73(2):176-181
This paper presents comprehensive results of the eco-friendly, large scale fabrication of nearly spherical Ho3+-doped Y2O3 submicron particles, synthesized using the urea homogeneous precipitation method. The dependence of the photoluminescence emission on the doping concentration was examined to determine the optimum Ho3+ concentration in the samples. X-ray diffraction data of the Y2O3:Ho3+ particles revealed a cubic Y2O3 structure. Field emission scanning electron microscopy confirmed the formation of nearly spherical shape particles with a mean diameter of 200±50 nm. The luminescence emission intensity significantly increased with increasing calcination temperature due to the improved crystallinity of the synthesized particles. Strong visible green-yellowish emission due to 5F4; 5S2–5I8 Stokes transitions was observed under constant 450 nm excitation. Simple large scale fabrication along with the strong visible green-yellowish emission might give these particles wide area of applications. 相似文献
19.