Preferential Neighboring Substitution-Triggered Full Visible Spectrum Emission in Single-Phased Ca10.5-xMgx(PO4)7:Eu2+ Phosphors for High Color-Rendering White LEDs
Preferential Neighboring Substitution-Triggered Full Visible Spectrum Emission in Single-Phased Ca10.5-xMgx(PO4)7:Eu2+ Phosphors for High Color-Rendering White LEDs
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用于高显色性白光 LED 的单相 Ca10.5-xMgx(PO4)(7):Eu2 荧光粉中优先邻近取代触发的全可见光谱发射
DOI：
10.1021/acsami.8b11879
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发表时间：
2018-10-03
影响因子：
9.5
通讯作者：
Zhang, Yu
中科院分区：
文献类型：
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作者：
Leng, Zhihua;Li, Renfu;Zhang, Yu
控制稀土激活剂在多个阳离子晶格中的分布可以实现单相荧光粉转换的白色发光二极管(LED)的多种颜色输出。然而，由于稀土激活剂的分布不确定，以及白色LED的三原色特殊组合，成功的案例几乎没有报道。在本论文中，我们以白锁石β-Ca-3(PO4)(2)为多阳离子晶格基质来调控Eu2+激活剂的再分配，并首次报道了在Ca10.5-xMgx(PO4)(7)：Eu2+系列荧光粉中，由镁离子引导的Eu2+激活剂在不同钙位之间的重新分配来调节发光行为。Ca(5)和Ca(4)位上较小的Mg2+离子的择优邻近取代引发了沿c轴的局域结构的不连续演化，并诱导了共价可变的Ca(1)、Ca(2)和Ca(3)阳离子位来容纳Eu2+激活剂。独特的光学特性使单相Ca9.75Mg0.75(PO4)(7)：Eu2+荧光粉转换的白色LED显示出相当高的显色指数R-a(85)和R-9(91)值。本文报道的择优邻近阳离子取代不仅可以控制Eu2+激活剂在不同阳离子位置之间的迁移以获得可调的发光性能，而且还为下一代高质量的固体照明开辟了一条新的途径。
Manipulating the distribution of rare-earth activators in multiple cation lattices can achieve versatile color output for single-phased phosphor-converted white light-emitting diodes (LEDs). However, successful cases are barely reported, owing to the uncertain distribution of rare-earth activators and the special combination of three primary colors for white LEDs. Herein, we took whitlockite beta-Ca-3(PO4)(2) as a multiple cation lattice host to manipulate the redistribution of Eu2+ activators, and the surprising Mg2+-guided redistribution of Eu2+ activators among different Ca sites is reported for the first time to regulate the photoluminescence (PL) behavior in series Ca10.5-xMgx(PO4)(7):Eu2+ phosphors. The preferential neighboring substitution of smaller Mg2+ cations in Ca(5) and Ca(4) sites triggers a discontinuous evolution of local structure along c axis and induces covalent variable Ca(1), Ca(2), and Ca(3) cation sites for the accommodation of Eu2+ activators. The unique optical feature enables the single-phased Ca9.75Mg0.75(PO4)(7):Eu2+ phosphor-converted white LED to exhibit quite high color-rendering index R-a (85) and R-9 (91) values. The preferential neighboring-cation substitution reported here can not only manipulate the migration of Eu2+ activators among different cation sites for tunable PL properties, but also carve out a new way for next-generation high-quality solid-state lighting.