Guo Ning, You Hongpeng, Jia Chengzheng, Ouyang Ruizhuo, Wu Dahui
School of Science, University of Shanghai for Science and Technology, Shanghai 200093, P. R. China.
Dalton Trans. 2014 Aug 28;43(32):12373-9. doi: 10.1039/c4dt01021c.
In this study, we synthesized and characterized a series of Eu(2+) and Mn(2+)-coactivated fluoro-apatite-structure Ca6Y2Na2(PO4)6F2 phosphors, which can provide high-quality standard white emission from a single-phase host. The powder X-ray diffraction, photoluminescence spectra, fluorescence decay curves, chromaticity coordinates, and correlated color temperature of the obtained phosphors were measured and are discussed in detail. Energy transfer from the Eu(2+) to the Mn(2+) ions was demonstrated by the overlap between the emission spectrum of the Eu(2+) ions and the excitation spectrum of the Mn(2+) ions, and the systematic relative decline and growth of the emission bands of Eu(2+) and Mn(2+), respectively. A possible energy transfer mechanism was proposed based on the experimental results and analysis. It was discovered that the emission colors of the phosphor varied from blue through white and eventually to yellow by properly tuning the doping content of Mn(2+) with a fixed Eu(2+) content through the principle of energy transfer. The developed phosphors can be efficiently excited in the UV region and exhibit white-light emission, making them attractive as white-emitting conversion phosphors for UV-based white light emitting diodes.
在本研究中，我们合成并表征了一系列铕（Eu(2+)）和锰（Mn(2+)）共激活的氟磷灰石结构Ca6Y2Na2(PO4)6F2荧光粉，其可从单相基质提供高质量的标准白色发射。对所得荧光粉的粉末X射线衍射、光致发光光谱、荧光衰减曲线、色度坐标和相关色温进行了测量并详细讨论。通过Eu(2+)离子的发射光谱与Mn(2+)离子的激发光谱之间的重叠，以及Eu(2+)和Mn(2+)发射带分别的系统性相对下降和增长，证明了从Eu(2+)到Mn(2+)离子的能量转移。基于实验结果和分析提出了一种可能的能量转移机制。通过能量转移原理，在固定Eu(2+)含量的情况下适当调整Mn(2+)的掺杂含量，发现荧光粉的发射颜色从蓝色经白色最终变为黄色。所开发的荧光粉可在紫外区域被有效激发并呈现白光发射，使其作为基于紫外的白光发光二极管的白光发射转换荧光粉具有吸引力。
