中文摘要：

制备了基于小分子tris-（8-hydroxyquinoline）aluminum（III）（Alq3）的有机发光二极管,并在室温下对器件进行大电流老化处理;然后测量了器件的光电性能,以及电致发光磁效应（magneto-electroluminescence,MEL）随老化时间的变化关系.实验结果显示,经老化处理后,器件的发光效率降低、工作电压增大;但器件的MEL随老化时间则表现出先增加、后减小的特点,且其线型保持不变.基于器件光电性能退化的主要机制,分析了器件MEL发生非单调变化的可能原因,即器件中形成了对发光激子有淬灭作用的Alq3阳离子,该阳离子引起发光强度的减弱造成MEL在短时间处理后增加,而阴极/Alq3界面的退化导致发光层中电场的增大则引起器件MEL的减小.这对理解有机发光的退化机制和有机磁效应的形成机制具有较好的促进作用.

英文摘要：

We investigated the influence of electric stress condition on organic magneto-electroluminescence（MEL） in tri-（8-hydroxyquinoline）aluminum（Alq3）-based organic light-emitting diodes.The results show that the performance of the devices goes to bad as increasing the aging time;in particular,the threshold voltage becomes larger and the luminescence efficiency gets lower.Moreover,the magnitude of the MEL increases firstly and then gets smaller with the line shape unchanged as the device aging.Possible explanations for the above effects were proposed based on the mechanism of the device aging.We suggested that the quencher,Alq3 cation-radicals,which formed in the emitting layer,reduce the EL intensity and enhance the magnitude of MEL.In addition,the increase in turn-on voltage and the decrease in MEL are assigned to the degradation at the interface of Al/Alq3.