SrAl_2O_4∶Eu∶Dy荧光材料的低温余辉特性研究

Study on the long-lasting phosphorescence of SrAl_2O_4∶Eu∶DY at low temperature

利用自行设计的宽量程高低温复合灯照试验箱,首次检测分析了用高温固相法自制的及市售优质SrAl2O4∶Eu∶Dy荧光粉体的低温余辉特性。研究结果表明,以SrAl2O4∶Eu∶Dy为代表的铝酸盐基长余辉发光材料存在 223K左右的低温荧光“猝灭”现象,不同来源的同类材料“猝灭”阈值温度有所差异;SrAl2O4∶Eu∶Dy低温余辉特性的一般规律为随温度降低,余辉亮度衰减加快,但衰减曲线仍同室温下一样由快衰减陡降区和慢衰减平台区两部分构成, 273K时平台余辉亮度只有室温下的约1 /2,而 253K时仅余 1 /3左右。理论分析认为造成余辉性能低温变差的原因在于,热扰动源减弱使得捕获于陷阱中的受激电子被热激释放出来的几率降低,从而导致辐射退激发电子数的减少,余辉亮度降低。

The characteristics of the long lasting phosphorescence of SrAl 2O 4∶Eu∶Dy have been checked and analyzed at low temperature using self designed wide scale temperature testing box.The testing results revealed that there are low temperature sudden extinguishment phenomena in the long lasting phosphorescence of such kinds of materials, whose threshold temperature value (about 223 K) has a bit difference among them, and the general characteristics of long lasting phosphorescence at low temperature behaves as follows:comparing to that at room temperature (RM), faster decrease of phosphorescent brightness with the reduction of temperature, while decay curves still remain the same pattern composed of a quick decline part and a platform falling part in which the phosphorescent brightness at 273 K is only about 1/2 as big as that at RM and at 253 K the figure has changed to about 1/3. Finally,a brief analysis of previous observation has been made in theory.