采用高温还原法合成了Eu,Ti共激活橙红色Y2O2S长余辉发光材料,并测量了Y2O2S:0.03Eu,0.03Ti磷光体的荧光光谱,余辉分辨和余辉衰减曲线谱.实验结果表明,Y2O2S:0.03Eu,0.03Ti磷光体的发射谱由一系列Eu^3+离子内部能级跃迁的尖峰组成;余辉分辨谱则不同,由一个主峰位于565nm的宽发射带和一系列波长范围位于500nm以上的窄发射带两种峰形组成,可分别归为Ti离子的宽带余辉发射和三价Eu^3+的线状余辉发射,分析认为,样品中存在Ti余辉发射向Eu^3+内部能级间产生选择性的余辉传能机制,从而导致Y2O2S:0.03Ti,0.03Eu磷光体中同时出现两种发光中心离子的余辉分辨谱现象.
A new kind of orange-red long afterglow Eu and Ti co-doped Y2O2S phosphor was synthesized via a traditional solid state reaction method under reducing atmosphere of CO. The photoluminescence spectrum, afterglow time-resumed spectrum and afterglow decay curve of the Y2O2S:0.03Ti,0.03Eu phosphors were measured. The result shows that the emission spectrum of Y2O2S:0.03Ti,0.03Eu consists of a group of narrow linear peaks from charge transmission of Eu^3+. The orange-red afterglow was observed in present phosphors with two different luminescence centers: a broad yellow emission band around 565nm related to Ti emission and a group of narrow peaks of Eu^3+ emission in the longer wavelength range. The afterglow mechanism of Eu^3+ emission was suggested to come from the energy transfer process from Ti afterglow emission to Eu ions, and result in two different afterglow centers of Ti afterglow emission and Eu^3+ afterglow emission in present Y2O2S:0.03Ti,0.03Eu phosphor.