高效氟磷酸盐玻璃白光荧光体制备及发光特性

采用熔融淬火方法制备了一系列Sn²⁺,Dy³⁺单掺及Sn²⁺-Dy³⁺共掺氟磷酸盐玻璃荧光体。利用紫外-可见分光光度计分别对各玻璃荧光体的透过光谱、激发光谱、发射光谱及荧光寿命等进行了测试和分析。结果发现在紫外光激发下,对于Sn²⁺、Dy³⁺单掺氟磷酸盐玻璃可分别获得高效的蓝光与黄光发射,且Sn²⁺单掺氟磷酸盐玻璃荧光体发光显色指数和量子效率最高;对于Sn²⁺-Dy³⁺共掺氟磷酸盐玻璃荧光体可实现高效的白光发射,且发现在Sn²⁺和Dy³⁺之间存在明显的能量传递,通过调节Dy³⁺掺杂浓度,两离子之间的能量转移效率亦随之改变,从而可对其白光色度进行调节。当Dy³⁺掺杂浓度为3Wt%时,利用280nm商用LED芯片激发可获得对应色坐标为(0.311,0.330),量子效率为56.3%,亮度为6 706cd·m-2的近纯白光发射。此外,对各类玻璃样品的DSC、导热及其他光学性能也进行了测试与计算,获得了各样品的热导率、量子效率、色坐标、显色指数等参数。研究结果表明,制备的高效氟磷酸盐玻璃完全有望作为可调谐白光发光荧光体应用于商用LED。

Preparation and Photoluminescence Properties of Fluorophosphate Glasses with High Efficient White Light Emission

A series of Sn2+, Dy3+ and Sn2+-Dy3+ co-doped fluorophosphate glasses (FPGs) for white light emitting phosphor have been prepared by the melt quenching method. Under the UV light excitation, FPG: Sn2+ and FPG∶Dy3+ can obtain blue and yellow light, respectively. The emission color of FPG∶Sn2+-Dy3+ can be tuned from blue to white color by properly adjusting the concentration of Dy3+ ions under the excitation of 280 nm UV light, which can be attributed to the energy transfer from Sn2+ to Dy3+ ions. The energy transfer mechanism was investigated and analyzed according to the photoluminescence, lifetime decay and CIE chromaticity coordinate. In addition, the FPG∶Sn2+fluorophosphate glass shows the highest color rendering index of 94 and the quantum efficiency of 81.3%, and the Sn2+-Dy3+ co-doped fluorophosphate glasses show better white color coordinates. By controlling the concentration of Dy3+, the FPGs can present a white light with a CIE chromaticity coordinate of (0.311, 0.330), which is very close to the equal energy point. The corresponding quantum efficiency and the luminance are 56.3% and 6 706 cd·m-2, respectively. The results of this study demonstrate that the FPGs are promising candidate for commercial white light emitting applications.