【摘要】 采用CaxSi合金前驱物和Eu B6常压氮化制备了Ca Al Si N3∶Eu2+氮化物红色荧光粉。研究了不同烧结温度、添加助熔剂及二次烧结对发光性能的影响。通过扫描电子显微镜(SEM)、X射线衍射(XRD)、荧光分光光度计对发光材料的形貌、晶体结构、发光性能与热稳定性进行了研究。分析结果表明:通过合金前驱物常压氮化法得到的氮化物荧光粉具有Ca Al Si N3结构,空间群为Cmc21。Ca Al Si N3∶Eu2+红色荧光粉的最佳烧结温度为1 550℃。添加质量分数为6%的Sr F2助熔剂后,荧光粉发光强度的提升效果最好。添加6%Sr F2助熔剂及二次烧结后得到的荧光粉的晶粒生长更加完整,颗粒度明显改善,发射光谱的相对强度也明显提高,比未加助熔剂单次烧结的荧光粉相对强度提高了近一倍。将发射峰位在640 nm的Ca0.98Al Si N3∶0.02Eu2+红色荧光粉应用在白光LED的封装中,获得了色温为3 109 K、显色指数为92.5以及色温为4 989K、显色指数为95.8的高显色白光LED,说明本文合成的氮化物红色荧光粉可以实现暖白光和正白光高显色的白LED发光器件。更多还原

【Abstract】 Ca Al Si N3∶ Eu2 +red phosphors were synthesized through nitrating process under atmospheric pressure with CaxSi alloy as precursor and Eu B6 powder as activator. The influences of different sintering temperature,fluxing agent and secondary sintering on the characteristics of morphology,crystalline structure,luminescent properties and thermal stability of Ca Al Si N3∶ Eu2 +red phosphors were investigated by scanning electron microscopy( SEM),X-ray diffraction( XRD) and fluorescence spectrophotometer. It displays that the nitride synthetic has Ca Al Si N3 structure with space group Cmc21,and its optimum sintering temperature is 1 550 ℃. The performance of its luminous intensity was significantly enhanced when the mass fraction of Sr F2 flux was 6%. In the secondary sintering,the relative intensity of emission spectrum was nearly doubled,the grain size was optimized,and the relative intensity of the emission spectrum was also improved. Appling Ca0. 98 Al Si N3∶0. 02Eu2 +red phosphor with 640 nm emission wavelength in white LED packaging,the devices with high color rendering index of 92. 5 and 95. 8,corresponding color temperature of 3 109 K and4 989 K were obtained,respectively. The results indicate that the white LED emitting devices with high rendering index of positive white and warm white can be achieved by applying nitride synthetic.更多还原