Tunable silica shell and its modification on photoluminescent properties of Y2O3:Eu3+@SiO2 nanocomposites
Tunable silica shell and its modification on photoluminescent properties of Y2O3:Eu3+@SiO2 nanocomposites
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DOI：
10.1063/1.3694767
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发表时间：
2012-03
影响因子：
3.2
通讯作者：
Tong Liu;Wen Xu;X. Bai;Hongwei Song
中科院分区：
文献类型：
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作者：
Tong Liu;Wen Xu;X. Bai;Hongwei Song
核壳结构稀土掺杂纳米荧光粉由于其在生物成像方面的潜在应用而引起人们的广泛关注。了解核-壳结构对稀土离子光致发光（PL）性质的影响对于获得高效的纳米荧光粉具有重要意义。本文采用改进的Stober法合成了Y2 O3：Eu 3 +@SiO2复合材料，该材料具有固定的立方Y2 O3：Eu 3+核（约80 nm）和可控的SiO2壳层厚度（约3 - 21 nm），并通过X射线衍射、透射电子显微镜和傅里叶变换红外吸收光谱对其进行了表征。系统研究了Y2 O3：Eu 3+在254 nm电荷转移激发和7 FJ-5D2内壳层激发下（460-486 nm）的发光特性与SiO2壳层厚度和激发功率密度的关系。有趣的是，在7 FJ-5D2激发下，Eu ~（3+）的5D 0 - 7 F2/5D 0 - 7 FJ（J ~（2+））的强度比随壳层厚度的增加而显著增加。
The core-shell rare earth (RE) doped nanophosphors are attracting current interests owing to their potential application in bio-images. Understanding the modification of core-shell structure on photoluminescent (PL) properties of RE ions is important in obtaining efficient nanophosphors. In this paper, Y2O3:Eu3+@SiO2 composites with fixed cubic Y2O3:Eu3+ core (∼80 nm) and controllable thickness of silica shell (∼3−21 nm) were synthesized via a modified Stober method and characterized by x-ray diffraction patterns, transmission electronic microscope images, and Fourier-transform infrared absorption spectra. The dependences of PL properties of Y2O3:Eu3+ on the thickness of the silica shell and excitation power density were systemically studied under charge transfer excitation (254 nm) and 7FJ-5D2 inner-shell excitation (460-486 nm). It is interesting to observe that under 7FJ-5D2 excitation the intensity ratio of 5D0-7F2/5D0-7FJ (J ≠ 2) for Eu3+ increases considerably with the increase of shell thickness an...