Abstract The powder samples of Ca9Sc(PO4)7:xDy3+ white emitting phosphors were prepared via a solid state reaction technique. The Ca9Sc(PO4)7:Dy3+ samples were researched by using the GSAS Rietveld refinement and X-ray diffraction (XRD) methods, and SEM images and elemental maps were recorded. Under 350 nm excitation, the emission spectra of Ca9Sc(PO4)7:xDy3+ samples have two obvious peaks and one weak peak at 484, 572 and 660 nm, corresponding to the characteristic electron transitions of (4F9/2 → 6H15/2, blue), (4F9/2 → 6H13/2, yellow) and (4F9/2 → 6H11/2, red), respectively. The concentration quenching effect, decay lifetime and thermal quenching of the as-synthesized Ca9Sc(PO4)7:Dy3+ samples were researched systematically The Ca9Sc(PO4)7:0.02Dy3+ phosphor possesses a good thermal stability, of which the emission intensity at 423 K can maintain 79% of the initial value (273 K). In addition, through the study of the chromaticity coordinates of the Ca9Sc(PO4)7:0.02Dy3+ phosphor, it is found that it is located in the white region, and the Commission Internationalede L'Eclairage (CIE) chromaticity coordinates are (0.339, 0.389). The above results show that Ca9Sc(PO4)7:xDy3+ phosphors can be excellent candidate material for applications in NUV-excited white LEDs.

中文翻译：

---

用于 NUV 激发白光 LED 的新型热稳定 Dy3+ 掺杂 Ca9Sc(PO4)7 荧光粉的合成、结构和光学特性

摘要 采用固相反应技术制备了Ca9Sc(PO4)7:xDy3+白色荧光粉粉末样品。采用 GSAS Rietveld 精修和 X 射线衍射 (XRD) 方法对 Ca9Sc(PO4)7:Dy3+ 样品进行了研究，并记录了 SEM 图像和元素图。在350 nm激发下，Ca9Sc(PO4)7:xDy3+样品的发射光谱在484、572和660 nm处有两个明显峰和一个弱峰，对应于(4F9/2 → 6H15/2，蓝色)的特征电子跃迁）、（4F9/2 → 6H13/2，黄色）和（4F9/2 → 6H11/2，红色）。系统研究了合成的Ca9Sc(PO4)7:Dy3+样品的浓度猝灭效应、衰变寿命和热猝灭Ca9Sc(PO4)7:0.02Dy3+荧光粉具有良好的热稳定性，其中在 423 K 时的发射强度可以保持初始值（273 K）的 79%。另外，通过对Ca9Sc(PO4)7:0.02Dy3+荧光粉色度坐标的研究，发现它位于白色区域，国际照明委员会(CIE)色度坐标为(0.339, 0.389）。上述结果表明，Ca9Sc(PO4)7:xDy3+ 荧光粉可以成为 NUV 激发白光 LED 应用的极好候选材料。