激基复合物发光器件中三重激发态之间的湮灭过程  

Triplet-triplet annihilation process in exciplex-based organic light-emitting diodes

作　　者：令勇洲[1] 贾伟尧[1] 张巧明[1] 赵晨晓[1] 卢晨蕾 刘虹[1] 熊祖洪[1] 

机构地区：[1]西南大学物理科学与技术学院,发光与实时分析教育部重点实验室,重庆400715

出　　处：《科学通报》2015年第11期1022-1029,共8页Chinese Science Bulletin

基　　金：国家自然科学基金(11374242,11404266);重庆市科委自然科学基金(CSTC,2010BA6002);中央高校基本科研业务费专项资金(XDJK2014C081)资助

摘　　要：激基复合物中三重态湮灭形成单重态发光是一个相邻四分子间的相互作用过程,通常很难发生.本文通过近些年发展起来的有机磁效应这一灵敏的非接触式研究新方法,在单重态和三重态间的能量差(?EST)较小和给体分子三重态能量较高的激基复合物发光器件中观察到了三重态湮灭这一过程.器件光谱证明激基复合物激发态的形成,结果显示:温度大于100 K时,激基复合物器件的电致发光磁效应(?EL/EL)未呈现出高场下降现象;只有当温度降低到最低(20 K)时,器件才会呈现高场下降现象,且这一趋势,与器件的外加偏压(即注入电流密度)有关;?EL/EL随温度变化的这一趋势进一步证实了这一湮灭过程的存在.基于上述实验结果,初步探讨了在激基复合物发光器件中的三重态激发态间湮灭的形成条件.利用有机磁效应研究激基复合物发光器件中的微观机制对进一步提高器件的发光效率有重要的科学价值和潜在的应用前景.The triplet-triplet annihilation process in exciplex-based devices is hardly considered to occur at all because it is a four-intermolecular- interaction process. In this work, the annihilation process was observed in an exciplex-based device with a higher donortriplet energy and a greater energy difference between the singlet and triplet states by using the magnetic field effects （MFEs） as a new non-contact measurement approach. The red-shifted emission of the spectrum suggests that the exciplex state did indeed form. The MFE results show that the magneto-electroluminescence （AEL/EL） does not decrease remarkably under higher magnetic fields （B〉40 mT） at temperatures higher than 100 K （T〉100 K）; however, decreasing AEL/EL will only appear when the measurement temperature is reduced to the minimum （20 K） temperature. In addition, the decreasing AEL/EL also depends on the current density. The evolution of AEL/EL at different voltages and temperatures further confirmed the existence of the annihilation process. The annihilation process formation conditions for exciplex-based devices were also discussed based on the experimental results.

关 键 词：有机发光 激基复合物 有机磁效应 三重态湮灭 

分 类 号：TN383.1[电子电信—物理电子学]