Preparation and Luminescence Characteristics of Ca3Y2（BO3）4：Eu^3＋ Phosphor

Ca3Y2 （BO3）4：Eu^3＋ phosphor is synthesized by high temperature solid-state reaction method, and the Iuminescence characteristics are investigated. The emission spectrum exhibits two strong red emissions at 613 and 621 nm corresponding to the electric dipole ^5 Do- ^7F2 transition of Eu^3＋ under 365 nm excitation, the reason is that Eu^3＋ substituting for Y^3＋ occupies the non-centrosymmetric position in the crystal structure of Ca3 Y2 （BO3）4. The excitation spectrum for 613 nm indicates that the phosphor can be effectively excited by ultraviolet （UV） （254 nm, 365nm and 400nm） and blue （470nm） light. The effect of Eu^3＋ concentration on the emission intensity of Ca3 Y2 （BO3）4 ：Eu^3＋ phosphor is measured, the result shows that the emission intensities increase with increasing Eu^3＋ concentration, then decrease. The CIE colour coordinates of Ca3Y2 （BO3）4：Eu^3＋ phosphor is （0.639, 0.357） at 15mol% Eu^3＋.     

Ca4LaNbMo4O20:Pr3+荧光粉的发光性质

采用高温固相法成功制备出荧光粉Ca₄LaNbMo₄O₂₀:Pr³⁺,通过X射线衍射分析了样品的结构,其结构与CaMoO₄结构相似。在Ca₄LaNbMo₄O₂₀:Pr³⁺的激发光谱中出现了NbO₄^3-和MoO₄^2-的电荷迁移(CTS)吸收和Pr³⁺离子的4f→4f5d激发跃迁,以及Pr³⁺-金属离子的价间电荷迁移(IVCT)吸收;另外在420~520 nm处,还观测到属于Pr³⁺离子的典型f-f激发跃迁。发射光谱中,在452 nm激发下,主要出现绿光和红光两种发射,其峰值位于490 nm和607 nm处,分别是Pr³⁺的³P₀→³H₄和¹D₂→³H₄的跃迁作用;在紫外287 nm激发下出现NbO₄^3-和MoO₄^2-发射和Pr³⁺离子的4f5d→4f跃迁宽带,以及Pr³⁺离子的4f→4f发射峰。     

Intrinsic photoluminescence properties of amorphous Si3B3N7 ceramic

Amorphous Si₃B₃N₇ ceramic shows intrinsic photoluminescence. Three distinctive emission regions have been observed. Excitation with wavelengths between 254 and 330 nm stimulates intense blue emissions with peak maxima ranging from 447 to 479 nm. Exciting between 315 and 420 nm results in two broad emission peaks; the first in the range between 400 and 440 nm, and the second between 560 and 690 nm. Of these two latter emissions, the one in the violet region dominates in intensity over the other one in the red region, thus a violet color is perceived with the eye via excitation with 330 nm or higher wavelengths. The three distinct intrinsic emissions in the photoluminescence spectrum of amorphous Si₃B₃N₇ ceramic are related to defect centers in three topologically different regions in its structure. Dependence of emission on excitation wavelength is associated with the Red-Edge Effect and can be explained with a reabsorption mechanism at the red excitation edge.     

Influence of excitation light wavelength on the photoluminescence properties for ZnO films prepared by magnetron sputtering

Highly orientated polycrystalline ZnO films were deposited on sapphire, silicon and quartz substrates at room temperature by r.f. magnetron sputtering. Different photoluminescence (PL) spectra were observed when excited with different wavelength light. A UV emission peak (356 nm) and a blue peak (446 nm) were generated for the films on sapphire, silicon and quartz substrates, and only the 446 nm blue emission appeared for the films on glass substrates when the wavelength of the excitation light was 270 nm. With increasing the wavelength of the excitation light up to 300 and 320 nm, the UV emission disappeared for films on various substrates and the wavelength of the PL peaks increased up to 488 and 516 nm, respectively. When the wavelength of the excitation light increased to 398 nm, the PL spectrum becomes a wide band that is consistent with three emission peaks.     

铜掺杂氧化锌纳米棒的非线性光学响应竞争特性

利用飞秒脉冲激光激发Cu掺杂ZnO纳米棒,研究其特有的非线性光学性质和激发机制。在激发波长为750 nm的荧光光谱中,二次谐波峰非常弱,几乎可以忽略,存在非常强的激子发光峰和Cu掺杂导致缺陷发光峰。激发强度的增大会导致这两个发光峰强度呈非线性增大,激子发光峰位产生明显红移,而缺陷发光峰位没有变化。进一步增大激发强度,缺陷发光峰强度会出现饱和甚至有所下降,而激子发光峰强度持续增大。当激发波长增加到760 nm时,从样品的荧光光谱可以清楚地识别到二次谐波峰和激子发光峰以及缺陷发光峰并存。随着激发波长的进一步增加,二次谐波强度不断增大,而激子发光峰和缺陷发光峰的强度却随之下降。当激发波长为790 nm和800 nm时,未发现激子发光峰和缺陷发光峰,非线性光谱以二次谐波为主导。研究结果表明,通过选择合适的激发波长和激发强度,可以实现发光颜色的转变,使得Cu掺杂ZnO纳米棒在全光显示方面具有潜在的发展前景。     

Ni2+ emission in SrF2

Luminescence measurements of X-irradiated SrF₂:Ni are reported. After X-irradiation two emission bands have been found. One of them peaked at 293 nm and has an excitation band at 267 nm. The other one at about 770 nm, which is much weaker, has an excitation band at 274 nm. Both emission bands are also observed under X-ray excitation. A comparison with some previous studies of the absorption and thermoluminescence properties of X-irradiated SrF₂:Ni indicates that the emission bands are due to two different kinds of Ni²⁺ centers. The proposed emission mechanisms are similar to those found in CaF₂:Ni.     

常用合成食品色素荧光光谱研究

分析合成食品色素的分子结构特点,根据荧光与分子结构的关系,理论上推断合成食品色素是荧光物质。应用SP-2558多功能光谱测量系统,测得胭脂红、苋菜红、柠檬黄、日落黄、亮蓝等五种最常用的合成食品色素标准溶液的三维荧光光谱。结果表明,胭脂红在波长330～430 nm的光激发下,产生较强荧光,荧光峰值波长为621 nm,最佳激发波长为376 nm;苋菜红在波长300～440 nm的光激发下,产生较强荧光,荧光峰值波长为643 nm,最佳激发波长为370 nm;柠檬黄在波长280～380 nm的光激发下,产生很强荧光,荧光峰值波长为565 nm,最佳激发波长为315 nm;日落黄在波长310～410 nm的光激发下,产生较强荧光,荧光峰值波长为592 nm,最佳激发波长为348 nm;亮蓝在波长320～390 nm的光激发下,产生较强荧光,荧光峰值波长为456 nm,最佳激发波长为350 nm。进而对这五种合成食品色素的荧光光谱进行了分析讨论。结果可为食品色素检测和食品安全提供帮助。     

乙醚溶液荧光光谱特性及其机理研究

研究了低浓度乙醚水溶液在紫外光激励下的荧光光谱,以及其荧光特性随激发光波长和乙醚溶液浓度改变的变化规律,并对其产生机理和谱线特性进行了分析和探讨。结果显示,乙醚溶液在306 nm附近出现明显的荧光峰,其最佳激励波长为245 nm,且在292 nm处还有次峰出现。激发光波长改变时,相应的荧光峰值位置基本不变,且荧光峰的强度随激发光波长的变化呈高斯分布。荧光次峰和主峰的强度产生竞争。随浓度增加,306 nm处的荧光强度线性增强,当增至7%后,发生浓度猝灭,强度线性减弱。研究结果将为检测有毒、麻醉物质——乙醚的浓度及纯度等提供参考。     

Fabrication and characterization of Au/SiO2 nanocomposite films

Au/SiO₂ nanocomposite films were prepared by radio frequency sputtering technique and annealing. The above nanocomposite films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic force microscopy (AFM). The surface of the nanocomposite films was uniform with the particle diameter of 100-300 nm. The size of Au crystallites increased on increasing annealing time. The luminescent behavior of the nanocomposite films was characterized by photoluminescence (PL) with different excitation wavelengths. Two emission peaks at around 525 nm and 560 nm were observed with the excitation wavelength at 325 nm. An intensive emission peak at around 325 nm was observed with the excitation wavelength at 250 nm, which is related to the defective structure of the amorphous SiO₂ layer because of oxygen deficiency, and could be applied to many fields, such as ultraviolet laser and ultraviolet detector.     

Luminescent Characteristics of LiSrBO3：Eu3＋ Phosphor for White Light Emitting Diode

LiSrBO3 ：Eu3＋ phosphor is synthesized by a high solid-state reaction method, and its luminescent characteristics are investigated. The emission and excitation spectra of LiSrBO3：Eu3＋ phosphors exhibit that the phosphors can be effectively excited by near ultraviolet （401 nm） and blue （471 nm） light, and emit 615nm red light. The effect of Eua＋ concentration on the emission spectrum of LiSrBO3：Eu3＋ phosphor is studied; the results show that the emission intensity increases with increasing Eu3＋ concentration, and then decreases because of concentration quenching. It reaches the maximum at 3mol%, and the concentration self-quenching mechanism is the dipoledipole interaction according to the Dexter theory. Under the conditions of charge compensation Li＋, Na＋ or K＋ incorporated in LiSrBO3, the luminescent intensities of LiSrBO3 ：Eua＋ phosphor are enhanced.     

Er3+离子掺杂钡镓锗玻璃上转换发光机理研究

研究了Er³⁺离子掺杂钡镓锗玻璃的吸收光谱、拉曼光谱和上转换光谱.分析了Er³⁺离子在钡镓锗玻璃中的上转换发光机理.结果表明：玻璃的最大声子能量为828cm^-1，紫外截止波长为275nm.采用800nm和980nmLD激发玻璃样品，在室温下观察到强烈的上转换绿光和红光发射.随着Er³⁺离子浓度的增加，绿光发光强度先增加后减小，而红光发光强度呈单调递增趋势.能量分析表明：800nmLD激发产生的绿光主要源于Er³⁺离子4I_13/2能级的激发态吸收过程；红光发射主要源于Er³⁺离子4I_13/2能级与4I_11/2能级之间的能量转移过程.980nmLD激发产生的绿光主要源于Er³⁺离子4I_11/2能级之间的能量转移过程；而红光发射主要源于Er³⁺离子4I_13/2能级与4I_11/2能级之间的能量转移过程和4I_13/2能级的激发态吸收过程.通过量子效率分析，发现采用800nmLD激发Er³⁺离子掺杂浓度为1mol% 的样品时，上转换绿光发光效率最高. 关键词： 上转换发光机理 3+离子掺杂')" href="#">Er³⁺离子掺杂 钡镓锗玻璃     

Dy3+ emission in M5(PO4)3F (M = Ca, Ba) phosphor

Ultrafine M₅(PO₄)₃F:Dy³⁺ (M = Ca, Ba) phosphors were prepared via combustion process using metal nitrates as precursors. The formation of crystalline phosphate was confirmed by X-ray diffraction pattern. The PL excitation spectra show the excitation peaks observed at 250 to 400 nm due to f → f transition of Dy³⁺ ion, which are useful for solid-state lighting purpose (mercury free excitation). The PL emission of Dy³⁺ ion by 348 nm excitation gave an emission at 489 nm (blue), 582 nm (yellow) and 675 nm (red). All the characteristics of BYR emissions like BGR indicate that Dy doped Ca₅(PO₄)₃F and Ba₅(PO₄)₃F phosphors are good candidates that can be applied in solid-state lighting phosphor (mercury free excited lamp phosphor) and white light LED.      

Ca3Y2Si3O12：Tm3+,Yb3+上转换发光粉的制备与发光性能研究

采用高温固相法成功制备了Ca₃Y₂Si₃O₁₂：Tm³⁺,Yb³⁺上转换蓝色发光材料。在980 nm 红外激光器激发下,发光粉呈现强烈的蓝光（475 nm）和近红外光（810 nm）以及较弱的红光（650 nm）发射,分别归因于Tm³⁺离子的¹G₄→³H₆、³H₄→³H₆和¹G₄→³F₄能级跃迁。随着Yb³⁺离子浓度的增加,发光粉上转换发射强度和发光亮度均呈现先增强后减弱的变化趋势。在最佳掺杂浓度下（Yb³⁺摩尔分数为15%）,蓝、红光强度分支比为12：1,色坐标为（0.129 2,0.152 3）。在3.9 W/cm²激发功率密度下,发光亮度可达6.8 cd/m²。上述结果证实,所制备发光粉呈现优异的蓝光上转换发射特性并具有潜在的应用价值。发光强度和激发光功率关系表明,所得上转换发射为三光子和双光子吸收过程。借助Tm-Yb体系能级结构详细讨论了上转换发射的跃迁机制。     

不同波长激发光对血清荧光光谱影响的实验研究

采用日本岛津荧光光度计RF5301,研究了血清的荧光光谱与激发光波长的关系。实验结果表明：在不同波长的紫外光激励下,血清产生的荧光光谱线型及峰值波长基本相同,与激励光波长无关,但荧光峰强度随激励光波长变化而变化。血清的荧光光谱有两个较强的荧光发射区,其中第一个发射区处于300～410 nm,第二个发射区处于410～530 nm。当激发光波长小于310 nm,荧光主要集中在第一发射区,荧光峰位于330和370 nm处,并产生竞争现象。当激发光波长大于250 nm时,只出现330 nm处的荧光峰,其最佳激励光波长为300 nm;当激发光波长大于320 nm,第一发射区的荧光变弱,在第二发射区的荧光变强,荧光峰位于452 nm。此研究为血液的光谱特性研究提供了实验依据,对光诱导荧光光谱诊断技术中激发光波长的选择具有一定的参考价值。     

发光二极管用SrWO4:Eu3+红光荧光粉激发谱强度的调控

采用化学共沉淀法制备了Eu³⁺掺杂摩尔分数不同、煅烧温度不同的SrWO₄:Eu³⁺系列发光粉体, 所制备的粉体均具有Eu³⁺特征的强室温红光荧光发射. 通过调节煅烧温度和掺杂摩尔分数来调控近紫外和蓝光吸收强度, 进而调控用395 nm的近紫外光和465 nm的蓝光激发样品所得红光发光强度. 研究结果表明, 所制备的SrWO₄:Eu³⁺红光荧光粉可以被紫外和蓝光发光二极管有效激 关键词： 稀土掺杂 4:Eu³⁺')" href="#">SrWO₄:Eu³⁺ 光致发光 白光发光二极管     

金纳米颗粒的紫外、蓝紫光波段光致荧光特性

采用电化学方法制备出粒径在20～30 nm的悬浮胶体金纳米颗粒。研究了金纳米颗粒的荧光发射光谱特性。在377和459 nm观察到两个荧光发射峰,分别位于紫外和蓝紫光波段,对应的敏感激发波长为220 nm。减小激发光强度或降低金纳米颗粒的粒子数密度都会使377 nm处的荧光发射峰强度减弱。位于459 nm处的荧光发射峰对激发光强度和颗粒数密度变化更为敏感,并且在激发光强度降低到一定阈值或粒子数密度高于一定阈值后消失。随着激发光强度的增加,位于377和459 nm处的两发射峰强度逐渐靠近,其比值逼近于1。实验结果与随机分布介质的自组织散射式谐振腔理论符合得较好。这表明胶体金纳米颗粒中存在循环多重散射,并由此引发了蓝光及紫外波段的荧光增强,这在光存储和全色显示等方面具有潜在的应用前景。     

Ce3+/Tb3+/Sm3+共掺CaO-B2O3-SiO2玻璃的光学性能调控

采用高温熔融法制备了Ce³⁺/Tb³⁺/Sm³⁺掺杂的CaO-B₂O₃-SiO₂（CBS）发光玻璃。通过傅利叶红外光谱仪、荧光光谱仪表征了该系列发光玻璃的微观结构和发光性质,并对Ce³⁺到Tb³⁺、Ce³⁺到Sm³⁺之间的能量传递机制进行了研究。结果表明,在339,378,407 nm激发下,单掺Ce³⁺、Tb³⁺和Sm³⁺的CBS玻璃分别发射紫蓝光、绿光和红光,恰好符合混合合成白光的条件。Ce³⁺/Tb³⁺和Ce³⁺/Sm³⁺双掺CBS玻璃的发射光谱以及Ce³⁺衰减寿命的变化证实了Ce³⁺→Tb³⁺和Ce³⁺→Sm³⁺之间存在能量传递,随Tb³⁺和Sm³⁺浓度增加,Ce³⁺的寿命减小,且传递效率由5.4%和5.7%分别增加至24.0%和27.1%。调节3种稀土离子的掺杂浓度并选择合适的激发波长,实现了发光颜色可调,并最终获得白光发射。     

掺铒矾酸钇晶体上转换荧光研究

使用波长为808和658nm的半导体激光器和染料激光器作为激发源，测量了Er³⁺：YVO₄晶体的波长在553和410nm附近的上转换荧光.对激发过程的分析表明，贡献于上转换荧光的主要激发机制为激发态吸收.在不同浓度下对上转换荧光的寿命测量结果显示，随Er³⁺浓度的提高，553nm绿光的荧光寿命随浓度的增加而减小，但410nm的荧光寿命随Er³⁺浓度无明显变化.结合绿光强度随掺杂浓度增加而减小的结果，认为在所测浓度范围内 关键词：     

纳米相氟氧化物玻璃陶瓷中Er3+Yb3+离子对的量子剪裁发光造成的强的光谱调制

研究了纳米相氟氧化物玻璃陶瓷中Er3+Yb3+离子对的量子剪裁发光造成的强的光谱调制现象。测量了Er3+Yb3+双掺纳米相氟氧化物玻璃陶瓷的X射线衍射谱、表面形貌、激发光谱、吸收光谱、和发光光谱;而且也与Tb3+Yb3+双掺纳米相氟氧化物玻璃陶瓷的相对应的光谱参数进行了比较。发现378 nm光激发样品(A) Er(1%)Yb(8.0%)∶FOV和样品(B) Er(0.5%)Yb(3.0%)∶FOV所导致的652.0 nm红色发光强度为522 nm光激发时的680.85倍和303.80倍;我们还发现378 nm光激发所导致的样品(A) Er(1%)Yb(8.0%)∶FOV和样品(B) Er(0.5%)Yb(3.0%)∶FOV的 652.0 nm红色发光强度为样品(C) Er(0.5%)∶FOV 的491.05和184.12倍。我们还发现在378 nm光激发时的样品(A) Er(1%)Yb(8.0%)∶FOV和样品(B) Er(0.5%)Yb(3.0%)∶FOV的{978.0和1 012.0 nm}红外发光强度依次分别为样品(C) Er(0.5%)∶FOV 的{58.00和293.62}倍和{25.11和 67.50}倍。更进一步,对于652.0 nm波长发光的激发谱,发现(A) Er(1%)Yb(8.0%)∶FOV和(B) Er(0.5%)Yb(3.0%)∶FOV的378.5 nm激发谱峰强度是(C) Er(0.5%)∶FOV的大约606.02和199.83倍。同时,也发现样品(A) Er(1%)Yb(8.0%)∶FOV和样品(B) Er(0.5%)Yb(3.0%)∶FOV的一级量子剪裁红外1 012或978 nm发光强度为样品(D) Tb(0.7%)Yb(5.0%)∶FOV的二级量子剪裁红外976 nm发光强度的101.38和29.19倍。发现的该量子剪裁是目前所报道的最强的量子剪裁。因此,相信所发现的氟氧化物纳米玻璃陶瓷中Er3+Yb3+离子对的一级量子剪裁发光是强的可以作为量子剪裁层应用到提高晶硅太阳能电池的发电效率。研究结果也能加速对目前国际热点的下一代环保的光谱调制太阳能电池的探索。     

Energy transfer and excitation wavelength dependent long-lasting phosphorescence in Pr activated Y3Al5O12

Long-lasting phosphorescence (LLP) was observed in Pr³⁺-doped Y₃Al₅O₁₂ (YAG:Pr) after it was excited by 240 or 290 nm light. The photoluminescence (PL) and LLP properties were studied. It is interesting that the PL and LLP spectra were different. In the PL emission spectra both the emissions of d-f and f-f transitions of Pr³⁺ ions were observed. However, in the LLP spectra of YAG:Pr the emissions of d-f transition were absent. It is deduced that the differences were due to the energy transfer process between traps and emission centers. On the other hand, significant differences were observed between the two LLP spectra after the sample was excited by 240 and 290 nm lights, respectively. The thermoluminescence (TL) properties were also studied. It is suggested that these studies will be significant for understanding the mechanism of LLP phenomenon.