非稀土红色荧光粉Mn4+:Li2TiO3发光特性研究

Luminescent performances of non-rare earth Mn4+:Li2TiO3red phosphor s

摘要:

利用高温固相法成功合成了非稀土类红色荧光粉 Mn⁴⁺:Li₂TiO₃,并对所制得的样品进行X射线衍射(XRD)、吸收谱和荧光发射谱等 表征。在波长为475nm的LED蓝光照射时,获得了最大强度位于〖J P 〗682nm波长处的红色荧光,量 子效率约为10%,其对应Mn⁴⁺自旋²Eg→⁴A 2g。计 算了晶体场强度因子Dq和Racah参数B、C,并据此分析了Mn⁴⁺在Li₂TiO₃中的电 子云重排效应。通 过改变掺杂浓度,分析了Mn⁴⁺掺杂在Li₂TiO₃中的浓度淬灭效 应。最后进行了LED白光性能 测试。

Abstract:

Non-rare earth Mn⁴⁺:Li₂TiO_3red phosphors were synthesized through th e high temperature solid state reaction method.The structural and luminescent characterizations of the phosphors are described by analyzing X-ray diffraction (XRD),absorption spectrum and fluorescence emission spectrum.The p hosphors exhibit strong red emission at 682nm when it is excited by 475nm LED, with quantum efficiency approaching 10%,which is ascribed to the spin forbidden transition of ²Eg→⁴A_2g for.Th e Mn⁴⁺ ions crystal field strength (Dq) and the Racah parameters (B and C) are estimated to evaluate the nephelauxetic effect of Mn⁴⁺ in Li₂TiO_3host lattice.Concentr ation quenching effect of Mn⁴⁺ luminescence in Li₂TiO_3is presented.Th e white-LED properties are also measured.