Bluish-White Luminescence in Rare-Earth-Free Vanadate Garnet Phosphors: Structural Characterization of LiCa3MV3O12 (M = Zn and Mg)
Bluish-White Luminescence in Rare-Earth-Free Vanadate Garnet Phosphors: Structural Characterization of LiCa3MV3O12 (M = Zn and Mg)
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DOI：
10.1021/acs.inorgchem.7b02820
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发表时间：
2018-01-15
影响因子：
4.6
通讯作者：
Sato, Mineo
中科院分区：
文献类型：
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作者：
Hasegawa, Takuya;Abe, Yusuke;Sato, Mineo
广泛的注意力已经集中在廉价的和不含稀土的石榴石结构钒酸盐磷光体的研究上，其不具有低的光吸收，这是由于发光颜色容易通过其高的组成灵活性来控制。然而，具有高量子效率的蓝光发射磷光体至今尚未发现。在这项研究中，我们成功地发现了蓝白色发光，石榴石结构的LiCa3MV3O12（M = Zn和Mg）具有高量子效率的荧光粉，并通过Rietveld分析技术细化了详细的晶体结构。这些磷光体在341 nm的近紫外光激发下表现出在481 nm处的宽带发射光谱峰，表明发射光谱和激发光谱没有明显差异。在LiCa3MV3O12（M = Zn和Mg）磷光体中观察到非常紧凑的四面体[VO4]单元，这在其他常规石榴石化合物中看不到，并且产生蓝白色发射。此外，这些磷光体表现出分别为40.1%（M = Zn）和44.0%（M = Mg）的高量子效率。因此，这些钒酸盐石榴石荧光粉可以为LED器件提供新的蓝色光源。
Extensive attention has been focused toward studies on inexpensive and rare-earth-free garnet-structure vanadate phosphors, which do not have a low optical absorption due to the luminescence color being easily controlled by its high composition flexibility. However, bluish emission phosphors with a high quanturn efficiency have not been found until now. In this study, we successfully discovered bluish-white emitting, garnet structure-based LiCa3MV3O12 (M = Zn and Mg) phosphors with a high quantum efficiency, and the detailed crystal structure was refined by the Rietveld analysis technique. These phosphors exhibit a broad-band emission spectra peak at 481 nm under near UV-light excitation at 341 nm, indicating no clear difference in the emission and excitation spectra. A very compact tetrahedral [VO4] unit is observed in the LiCa3MV3O12 (M = Zn and Mg) phosphors, which is not seen in other conventional garnet compounds, and generates a bluish-white emission. In addition, these phosphors exhibit high quantum efficiencies of 40.1% (M = Zn) and 44.0% (M = Mg), respectively. Therefore, these vanadate garnet phosphors can provide a new blue color source for LED devices.