Photoluminescence properties of Eu(3+)-doped glaserite-type orthovanadates CsK(2)Gd[VO(4)](2).
Photoluminescence properties of Eu(3+)-doped glaserite-type orthovanadates CsK(2)Gd[VO(4)](2).
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DOI：
10.1021/ic500208h
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发表时间：
2014-04
影响因子：
4.6
通讯作者：
Zhengxu Tao;T. Tsuboi;Yanlin Huang;Wei Huang;P. Cai;H. Seo
中科院分区：
文献类型：
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作者：
Zhengxu Tao;T. Tsuboi;Yanlin Huang;Wei Huang;P. Cai;H. Seo
采用固相反应法合成了不同Eu（3+）浓度（x = 0，0.1，0.2，0.3，0.4，0.5，0.6，0.7，0.8，0.9和1.0）的未掺杂和Eu（3+）掺杂的钙钛矿型原钒酸盐CsK 2Gd 1-xEux[VO 4]2。通过X射线衍射研究证实了单相化合物的形成。研究了样品的光致发光（PL）和PL激发（PLE）光谱、PL衰减曲线和绝对量子效率（QE）。与传统的Eu（3+）掺杂钒酸盐不同，这些样品不仅表现出几条由Eu（3+）引起的尖锐发射线，而且由于[VO 4]（3-）基质的存在，还表现出一个最大位于530 nm的宽发射带。当Eu（3+）浓度从x = 0增加到x = 0.6时，基质和Eu（3+）发射的强度增加，当x = 0.6时，基质和Eu（3+）发射的强度降低。QE也观察到类似的浓度依赖性。即使在CsK 2 Eu（VO 4）的Eu（3+）凝聚的基质中，基质发射也从未被猝灭，表明从基质[VO 4]（3-）到Eu（3+）的能量转移效率低。这种低效率的能量转移是通过V-O-Eu键角偏离180°抑制能量转移以及Gd（3+）位的Eu（3+）离子与[VO 4]（3-）的分离来理解的。与530 nm的电荷转移[VO 4]（3-）发射一样，Eu（3+）的发射也有两个宽而强的PLE带，最大发射波长分别为330和312 nm。CsK_2Gd_（1-x）Eux [VO_4]_2（x = 0.6）的最大量子效率为38.5%。在530 nm宽的发射带和590-620 nm的Eu（3+）强的尖发射线的组合下，得到了白色的发射。
Undoped and Eu(3+)-doped glaserite-type orthovanadates CsK2Gd1-xEux[VO4]2 with various Eu(3+) concentrations of x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 were synthesized via the solid-state reaction. The formation of a single phase compound was verified through the X-ray diffraction studies. The photoluminescence (PL) and PL excitation (PLE) spectra, PL decay curves, and absolute quantum efficiency (QE) were investigated. Unlike the conventional Eu(3+)-doped vanadates, these Eu(3+)-doped samples showed not only several sharp emission lines due to Eu(3+) but also a broad emission band with a maximum at 530 nm due to the [VO4](3-) host. The intensities of the host and Eu(3+) emissions increased when the Eu(3+) concentration was increased from x = 0 to x = 0.6 and decreased above x = 0.6. Similar concentration dependence was observed for QE. The host emission, even if in the Eu(3+)-condensed host of CsK2Eu(VO4), was never quenched indicating inefficient energy transfer from the host [VO4](3-) to Eu(3+). This inefficient energy transfer is understood by suppression of the energy transfer by the V-O-Eu bond angle deviated from 180° and the separation of Eu(3+) ions at the Gd(3+) site from [VO4](3-). Like the 530 nm charge transfer [VO4](3-) emission, two broad and intense PLE bands with maxima at 330 and 312 nm were observed for the Eu(3+) emission. A maximum QE of 38.5% was obtained from CsK2Gd1-xEux[VO4]2 (x = 0.6). A white-colored emission was obtained by the combination of the broad 530 nm emission band and the intense sharp lines due to Eu(3+) at 590-620 nm.