以脲素为燃烧剂, 采用燃烧法在较低引发温度下快速合成了CaAl12O19∶xMn4+发光粉体。 采用正交分析法考查了煅烧温度、 Mn4+掺杂量、 燃烧剂用量和煅烧时间等合成条件对荧光粉发光强度的影响。 实验结果表明: 煅烧温度1 200 ℃, Mn4+掺杂量2%, 燃烧剂/CaAl12O19摩尔比为50∶1, 煅烧时间5 h为最佳合成工艺, 制得的荧光粉的发射强度为95.8。 该荧光粉由于Mn4+的2E—4A2跃迁, 在643和656 nm呈现强红色发光, 其中656 nm为最大发射峰; 在470 nm处的最大激发峰是属于Mn4+配位场的4A2—4T2跃迁, 470 nm激发峰可以与LED芯片的465 nm发射相匹配。

The CaAl12O19∶xMn4+ phosphor was rapidly synthesized at low temperatures with combustion method with urea as combustion agent. The influence of calcination temperature and time, the doping amount of Mn4+ ions, the molar ratio of combustion agent to CaAl12O19, on luminous intensity of fluorescent powder were examined with orthogonal analytical method. The optimum conditions for preparing phosphors are: sintering temperature 1 200 ℃, the amount of Mn4+ 0.02, the molar ratio of combustion agent to CaAl12O19 50∶1, and sintering time 5 hrs. The corresponding luminous intensity of this powder was 95.8, which is the largest. The phosphor shows a strong red luminescence at the 643 and 656 nm due to the 2E—4A2 transition of the Mn4+. The maximum excitation peak was at 470 nm due to the 4A2—4T2 transition of Mn4+ ligand field. The 470 nm excitation peak was matched with the 465 nm emission of the LED chips.