共查询到18条相似文献,搜索用时 109 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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溶胶-凝胶法引入烧结助剂制备SiC-Y3Al5O12复相陶瓷 总被引:4,自引:0,他引:4
以碳化硅、六水硝酸钇、九水硝酸铝和六次甲基四胺为主要原料,通过溶胶-凝胶法引入Al2O3和Y2O3复合烧结助剂,液相烧结制备得到SiC-Y3Al5O12(Y3Al5O12简称YAG)复相陶瓷.采用DTA、TEM、XRD等分析测试技术研究了溶胶-凝胶法引入复合烧结助剂过程及复合烧结助剂对SiC-YAG陶瓷的烧结性能、力学性能、物相组成与显微结构的影响.结果表明干凝胶在920℃左右已完全转变成YAG相,最终获得的YAG粒径小,并均匀分散在SiC表面的SiC-YAG复合粉体;复合粉体先干压、再等静压成型后,在1860℃下烧结45 min,所制得复相陶瓷的相对密度达到了96.5%,抗弯强度达到486 MPa,断裂韧性达到5.7 MPa·m1/2. 相似文献
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采用高温固相法合成白光LED用Ca1.55Y1.5Al3.5Si1.5O12:x Ce3+黄绿色荧光粉,利用X-射线粉末衍射和荧光光谱进行表征。实验结果表明,在紫外近紫外区(200~380nm)激发下荧光粉发射光谱主峰位于402nm,在蓝光454nm激发下荧光粉发射光谱主峰位于530nm。当灼烧温度为1623K,Ce3+掺杂浓度为10%,发光强度最高。随着Ce3+的掺杂增加会发生浓度猝灭。该荧光粉与商业近蓝光芯片发射相匹配,是一种优秀的白光LED用黄绿色荧光粉。 相似文献
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氧化铝超滤膜是一种新型的分离膜,性能优异,在生物医学等领域有广阔的应用前景。本文通过采用溶胶凝胶法制备Al_2O_3超滤膜的实验过程,重点研究影响Al_2O_3超滤膜制备的因素。 相似文献
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采用溶胶-凝胶法合成Y2O3:Tb3+纳米粒子。用红外光谱(IR)、X射线衍射(XRD)、光致发光(PL)光谱对其进行一系列表征。结果表明所制备的纳材料在400℃还没完全结晶,在1000℃时结晶完全,得到较纯产物且有良好的发光性能。 相似文献
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水热法制备Y2O3:Eu3+微米棒及其荧光性能表征 总被引:1,自引:0,他引:1
利用水热法制备了Y2O3和Y2O3:Eu3+,探讨了反应温度、反应时间及氢氧化钠溶液浓度对产物晶型的影响,确定了生成较好晶型的反应条件为:反应温度180℃,反应时间24 h,氢氧化钠溶液浓度2 mol/L. 研究了Y3+和Eu3+的配比对Y2O3:Eu3+荧光性能的影响. 结果表明,当n(Y3+):n(Eu3+)的比例为100:5时,其荧光强度最佳. TEM分析表明,Y2O3:Eu3+粉末具有直径约0.2~0.6 mm、长度为几到十几微米的棒状结构. 相似文献
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Weilun Zhang Yujun Liang Yingli Zhu Shiqi Liu Haoran Li Wen Lei 《Journal of the American Ceramic Society》2019,102(9):5223-5233
A series of Ce3+ and Tb3+ singly- and co-doped NaBa4(AlB4O9)2Cl3 (NBAC) phosphors have been synthesized via high-temperature solid state route. The crystal structure, morphology, photoluminescent properties, thermal properties and energy transfer process between Ce3+ and Tb3+ were systematically investigated. The structure refinements indicated that the phosphors based on NBAC crystallized in P42nm polar space group in monoclinic phase. The emission color could be tuned from blue (0.1595, 0.0955) to green (0.2689, 0.4334) via changing the ratio of Ce3+/Tb3+. The energy transfer mechanism of Ce3+/Tb3+ was verified to be dipole–quadrupole interaction via the examination of decay times of Ce3+ based on Dexter's theory. The good thermal stability showed the intensities of Ce3+ at 150°C were about 66.9% and 64.88% in NBAC:0.09Ce3+ and NBAC:0.09Ce3+, 0.07Tb3+ of that at room temperature, and the emission intensities of Tb3+ remained 102.41% in NBAC:0.11Tb3+ and 95.22% in NBAC:0.09Ce3+, 0.07Tb3+ due to the nephelauxetic shielding effect and the highly asymmetric rigid framework structure of NBAC. The maximum external quantum efficiency (EQE) of Ce3+ in NBAC:0.09Ce3+, yTb3+ phosphors could reach 43.38% at y = 0.13. Overall, all the results obtained suggested that NBAC:Ce3+, Tb3+ could be a promising option for n-UV pumped phosphors. 相似文献
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采用溶胶凝胶与沉淀相结合的方法和单一溶胶凝胶法制备Eu3+:Y2O3-3Si O2发光材料,通过DTA-TG、IR、XRD、TEM、激发光谱、发射光谱研究了材料的结构和发光性能。研究表明:两种方法制得的发光材料成分完全相同,但结构、形貌和发光性质有较大差别。IR确定结合法制备的材料主要存在Si-O-Si桥氧键,而单一法主要存在非桥氧的Si-O键;XRD确定结合法存在立方相的Y2O3,单一法主要存在非晶态Si O2,TEM显示结合法的形貌为纳米级球形Y2O3,单一法为纳米级棒状Y2O3。两种方法制得的样品Eu3+:Y2O3-3Si O2都显示Eu3+的特征发射峰位于613 nm;最佳激发峰分别在紫外区的257 nm和395 nm;两种方法制得的样品在相应最佳激发波长下,结合法制备出的荧光材料其发光强度和色纯度相对较高,半宽峰约为7 nm,两种方法制得的发光材料最佳退火温度均为800℃,Eu3+的最佳掺杂量均为6.0%。 相似文献
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Xinjian He Shengjuan Li Mingxue Deng Yangmin Tang Machao Wang Cheng Wang Zhenzhen Zhou Jiacheng Wang 《Journal of the American Ceramic Society》2024,107(4):2479-2493
Mixing multicolor phosphors for simulating the full spectrum of sunlight illumination is a popular solution to obtain high-quality white light. However, there is still a need to overcome the cyan gap in the emission spectrum. In this work, a series of garnet Ca2Y0.94–xLuxZr2–yHfyAl3O12:6%Ce3+ (abbreviated as CY0.94–xLuxZr2–yHfyA:Ce3+) cyan phosphors are designed and prepared by substituting Y3+ and Zr4+ in Ca2YZr2Al3O12:6%Ce3+ with Lu3+ and Hf4+ with smaller ionic radius and larger mass. Under 405 nm violet light excitation, the optimized Ca2Y0.88Lu0.06Hf2Al3O12:6%Ce3+ (CY0.88Lu0.06Hf2A:Ce3+) shows a bright cyan emission band in the range of 430–750 nm with the peak at 477 nm. Importantly, the emission intensity and thermal stability properties of CY0.88Lu0.06Hf2A:Ce3+ were significantly improved by 58% and 47% compared to those of pure Ca2YZr2Al3O12:Ce3+. Small and heavy cation substitution could induce highly stable rigid structure, thus enhancing emission intensity and stability. The color rendering index increases from 84.5 to 92.0 after supplementing CY0.88Lu0.06Hf2A:Ce3+ phosphor in white light-emitting diode devices combining commercial red, green, and blue phosphors with a violet chip, indicating its practical application in full-spectrum lighting. The present study provides promising strategies for the design and development of efficient cyan materials for high-quality full visible spectrum light-emitting diode lighting. 相似文献
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Eu3+,Ce3+共掺硼硅酸锌玻璃的发光性能及能量传递 总被引:1,自引:0,他引:1
采用高温液相法制备了50ZnO-30SiO2-20B2O3∶Eu3+,Ce3+玻璃。测试了样品的激发光谱和发射光谱。结果表明:在紫外光激发下,该玻璃可以发出明亮的红色光。其中580 nm,593 nm,617 nm,655 nm和706 nm波长处的发射峰分别对应于Eu3+的5D0→7F0,5D0→7F1,5D0→7F2,5D0→7F3和5D0→7F4跃迁发射,其中5D0→7F2跃迁发射强度最大,同时发现在450 nm处存在Ce3+的5D→2FJ(J=7/2,5/2)特征发射峰。首次发现在该发光玻璃50ZnO-30SiO2-20B2O3∶Eu3+,Ce3+中存在着Ce3+→Eu3+能量传递现象,其中Ce3+起敏化作用。 相似文献
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采用高温固相法制备了Ce3+激活的钇铝石榴石荧光粉Y3Al5O12:Ce3+(YAG:Ce3+)。采用X射线衍射法对所制备的样品进行结构分析,采用荧光光谱仪对样品进行发光分析。结果表明,在YAG:Ce3+的高温固相法制备过程中原材料和助熔剂用量以及稀土离子掺杂量、研磨时间、灼烧温度和时间等,都会对所制备样品的成相和发光性能产生影响。 相似文献