添加剂对CaS∶Eu磷光体发光性能的影响

Effects of additives on the luminescence properties of CaS∶Eu phosphor powders

为了使CaS∶Eu对外界激发光的吸收效率增强,通过添加几种廉价的添加剂,对传统的高温固相法进行了改进,制得了发光性能优异的CaS∶Eu磷光体;并采用XRD,UV-VIS,PL光谱等表征手段研究了添加剂对CaS∶Eu磷光体发光性能的影响。结果表明,制得的CaS∶Eu磷光体对紫外光和可见光特别是对绿光的吸收较大地增强了,CaS∶Eu磷光体的宽带红色发光效率明显增大,发射光谱和余辉光谱中未观察到3价铕的尖峰发射。CaS∶Eu磷光体上述发光性能改善的原因可归于杂相成分减少、主相硫化钙纯度提高、良好的气氛使得3价铕向2价铕的还原更彻底。

In order to enhance the absorption efficiency of CaS： Eu phosphor to the excitation light, the conventional high temperature solid- state method is improved by adding some low -cost additives. CaS： Eu phosphor powders,which have excellent luminescence properties, are prepared through this improved method. The effect of additives on their luminescence properties is investigated by X - ray diffraction （ XRD ） , UV - VIS spectrum and photoluminescence spectra （ PL ）. After adding some additives, the absorption of prepared CaS： Eu phosphor to UV or VIS light, especially to green light, and also their red - emitting efficiency are enhanced and the emission from Eu^3 ＋ ion cannot be found in these samples. All these improvements are due to the decrease of impurity phase CaO,increase of main phase CaS and thorough reduction of Eu^3＋ to Eu^2＋ under good atmospheres.