(Sr,Ca)AlSiN3:Eu2+荧光粉的常压合成及其LED封装性能研究

摘要

A series of ( Sr, Ca) AlSiN3: Eu2+ phosphors have been successfully prepared by solid state reaction under atmospheric pressure and the effect of synthetic methods ( atmospheric pressure synthesis and high pressure synthesis) on crystal structure, photoluminescence property and morphology of phosphor was also conducted. The ( Sr, Ca ) AlSiN3: Eu2+ phosphors prepared by atmospheric-pressure synthesis method exhibit an ideal luminescent intensity, and the emission peak located on 615 nm~640 nm. All the phosphors exhibit orthorhombic crystal structure similar with CaAlSiN3 structure. No impurity can be observed in XRD patterns of ( Sr, Ca) AlSiN3: Eu2+ phosphors. The obtained Sr0. 8 Ca0. 192 AlSiN3: 0. 008 Eu2+ phosphor was further used as efficient red component to fabricate white light emitting diodes ( LEDs) . Under the optimized condition of LED packaging, the white LEDs own the excellent optical properties with luminous efficiency of 86. 8 lm/W and an ideal color rendering index (Ra =85). Furthermore, the color correlated temperature (4000K~6000K) of white LEDs can be simply adjusted through changing the red phosphor ratio.%通过常压合成工艺成功制备了一系列高亮度的(Sr,Ca)AlSiN3:Eu2+氮化物荧光粉,比较了常压合成和高压合成工艺对荧光粉晶体结构、 光谱特性和晶体形貌的影响.荧光光谱分析表明,常压合成工艺制备的(Sr,Ca)AlSiN3:Eu2+荧光材料表现出优异的荧光强度,其发射波长位于615 nm~640 nm的红光范围,实现了一定范围内的光谱调控.X射线衍射结果表明,该氮化物红色荧光材料具有正交晶系的CaAlSiN3晶体结构,且产物中不存在杂质相.峰值波长位于615 nm和625 nm的样品能够作为光谱中的有效红色组成部分用以制备高显色性的白光LED光源.通过LED封装的优化实验,所获得的白光LED光源具有86.8 lm/W的流明效率,并具有良好的显色指数(Ra=85).进而,通过改变氮化物红粉的组成和比例能够制备具有不同色温(4000 K~6000 K)的白光LED光源.