共查询到17条相似文献,搜索用时 906 毫秒
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用溶胶凝胶法制备了一系列不同掺杂浓度的Y3Al5O12(YAG):Tb3+,Ce3+荧光粉,对其物相、光学性能和能量传递进行了研究。多晶粉末X-射线衍射结果表明,所有样品均为YAG晶相,没有其它杂相。当样品在Tb3+的特征激发峰273 nm激发时,除了Tb3+的特征发射外,还观察到位于467 nm的YAG基质的电荷迁移带、位于520 nm的Ce3+的2D3/2,5/2→2F5/2,7/2跃迁,这说明可能存在Tb3+到Ce3+的单向非辐射能量传递。通过监测共掺样品520 nm的发光,得到273 nm的激发峰,使得Tb3+(5D3)到Ce3+(2Di,i=5/2,3/2)的单向非辐射能量传递得到验证;并且随着掺杂Tb3+浓度的增大,273 nm激发峰增强。同时,Ce3+掺杂YAG:Tb3+并没有使Tb3+发光增强,相反YAG:Tb3+,Ce3+中Tb3+发光与YAG:Tb3+相比有1个数量级的减弱,造成这种情况的可能原因,一是Tb3+到Ce3+的单向非辐射能量传递,使得Tb3+发光减弱;二是Ce3+掺杂YAG:Tb3+后基质所多吸收的能量传给了Ce3+而非Tb3+。 相似文献
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采用固相法制备YAG∶Ce3+黄色荧光粉,以油酸、聚乙二醇、十二烷基磺酸钠和十二烷基硫酸钠等表面活性剂作为后处理剂,考察其种类、浓度和性质等对荧光粉发光性能的影响,进一步对浸泡温度以及浸泡时间等工艺条件进行了对比研究,并通过荧光光谱和扫描电子显微镜等手段对处理前后YAG∶Ce3+荧光粉的发光性能、表面形貌和老化性能等方面进行了表征和分析。结果表明,YAG∶Ce3+荧光粉的最佳后处理工艺条件为:十二烷基硫酸钠较为理想,经2.4%十二烷基硫酸钠处理后,YAG∶Ce3+荧光粉的发光强度约提高8.4%,浸泡温度为50℃,浸泡时间为60 min。 相似文献
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Mg~(2+)、Sr~(2+)离子掺杂对Ca_2Li_2BiV_3O_(12):Eu~(3+)发光性能的影响 总被引:1,自引:0,他引:1
采用高温固相法合成了Mg2+、Sr2+离子掺杂新型Ca2Li2BiV3 O12:Eu3+红色荧光粉体材料,研究了保温时间对Ca2 Li2 BiV3 O12:Eu3+荧光粉的影响。使用X射线衍射仪对合成样品进行物相分析,利用荧光分光光度计进行光谱分析,测试了样品的荧光光谱。样品表现为Eu3+离子的特征发射,发光强度随着保温时间的增加而逐渐增强。同时研究了Mg2+、Sr2+离子掺杂对合成荧光粉光谱对合成样品的发光性能的影响,本研究发现Mg2+离子掺杂后样品发光效果明显强于Sr2+离子掺杂后样品的发光效果。 相似文献
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用高温固相法合成了颜色可调的SrMoO4:xEu3+,yTb3+荧光粉,并对其发光粉结构及其发光特性进行了研究。结果表明,SrMoO4:xEu3+,yTb3+荧光粉属于四方结构。Eu3+离子在SrMoO4晶体中形成峰值为617 nm的5d→4f跃迁发光,Tb3+离子的5 D4→7 F5跃迁产生548 nm的绿光发射。两个发射带的激发光谱范围位于250~450 nm处,SrMoO4:xEu3+,yTb3+在紫外、近紫外波段内有很强的激发,是一种适合InGaN芯片激发的白光LED用荧光粉。 相似文献
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Yun‐Fang Wu Ya‐Han Chan Yung‐Tang Nien In‐Gann Chen 《Journal of the American Ceramic Society》2013,96(1):234-240
Ca3Sc2Si3O12:Ce3+ (CSS:Ce) green phosphors used for white light‐emitting diodes (LEDs) are synthesized and codoped with Al3+ via a solid‐state reaction method. The crystal structure and vibrational modes are analyzed by X‐ray diffraction, Fourier transform infrared spectroscopy, and Raman scattering spectroscopy. The energy transfer behavior and optical performance are characterized by photoluminescence and excitation spectra, quantum efficiency, and time‐resolved photoluminescence. The incorporation of Al3+ into CSS:Ce can inhibit the formation of the impurity phases Sc2O3 and CeO2, improve crystallinity, and enhance the photoluminescence intensity as well as quantum efficiency. The substitution of Sc3+ with Al3+ increased the crystal field splitting of Ce3+ and resulted in the red shift of photoluminescence. The results show that Ca3Sc2?xAlxSi3O12:Ce3+ has high quantum efficiency, making it a promising green phosphor that can be collocated with a commercial 450 nm blue LED and a red phosphor for solid‐state lighting applications. 相似文献
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Yanna Tian Yanru Tang Xuezhuan Yi Jie Chen Shiyu Sun Di Zhao Hui Lin Shengming Zhou 《Journal of the American Ceramic Society》2020,103(11):6453-6460
As a promising replacement for nitride red phosphors, Ce: Y3(Mg1.8Al1.4Si1.8)O12 (Ce: YMASG) ceramic phosphors have attracted significant attention recently for their advantages in inorganic encapsulation and massive red-shifting of Ce3+ emission. In this work, Ce: YMASG with different doping concentrations of Ce3+ and Al2O3, was fabricated by vacuum sintering to investigate its effects on the elimination of the impurity phase and the enhancement of the luminescent properties of white light-emitting diodes (w-LEDs). It was discovered that the emission wavelength redshifts from 592 to 606 nm as the Ce3+ concentration increases, while at 450 K, the emission intensity deteriorates from 0.47 to 0.36 of its initial value. The Rietveld analysis revealed the presence of an impurity phase of Y4MgSi3O13 with a concentration of 17.021 wt% in Ce: YMASG. With the introduction of Al2O3, the impurity phase was eliminated from the matrix completely, the emission peak shifted to a shorter wavelength, and the thermal stability was greatly improved. When the correlated color temperature was controlled at around 3000 K in the packaged w-LEDs, the commission international de l'éclairage (CIE) chromaticity coordinates shifted toward the bottom left corner of the diagram with increasing concentration of Ce3+. Conversely, the luminous efficiency (LE) increased from 36 lm/W to 58.6 lm/W as the concentration of Al2O3 increased from 0 to 10 wt%, which demonstrated the application prospect of the fabricated phosphor in warm w-LEDs. 相似文献