利用有机发光磁效应研究深蓝色激基复合物的发光机理

发布时间：2018-03-22 17:12

  本文选题：深蓝色激基复合物　切入点：有机磁效应　出处：《中国科学:技术科学》2017年04期 　论文类型：期刊论文

【摘要】：2013年Jankus等人在Advanced Materials上报道了NPB与TPBi共混的深蓝色激基复合物的发光机理,根据瞬态光谱的实验结果,他们认为器件中室温下较高的量子效率是由三重态激子的湮灭(TTA)导致的,而不是由热辅助引起的三重态激子T_1向单重态激子S_1的转变结果(即反向系间窜越,RISC).最近的研究表明,有机发光二极管(OLEDs)中的磁效应(magneto-electroluminescence,MEL)可作为研究其发光机理的有效手段,对TTA和RISC都有灵敏的指纹响应.本文制备了结构相同的OLEDs,测量了器件的MEL曲线,发现室温下该器件内部既没有发生TTA,也没有发生RISC过程,仅在低温20K且在大电流工作下才能出现TTA过程,采用更低功函数的阴极、对器件阳极进行臭氧O_3处理、甚至呈量级增大器件的注入电流,以有利于TTA过程的实现,但仍未观察到TTA,器件的磁电导实验结果及其理论模拟表明,该体系内部可能发生了三重态激子与空穴极化子的相互作用T_1(↑↑)+P~+(↓)→S_1(↑↓)+P~+(↑),即TPI(triplet-polaron interaction)过程,本研究对理解NPB与TPBi共混器件的发光机制有较好的参考价值.
[Abstract]:In 2013, Jankus et al reported on the luminescence mechanism of the dark blue excimer complexes of NPB and TPBi blends at Advanced Materials. Based on the experimental results of transient spectra, they concluded that the higher quantum efficiency at room temperature was caused by the annihilation of excitons in triplet states. Instead of the thermally assisted transformation of triplet excitons T1 to singlet excitons (i.e. reverse intersystem transitions), recent studies have shown that magneto-electroluminescence Mel in organic light-emitting diodes (OLEDs) can be an effective means of studying its luminescence mechanism. In this paper, OLEDs with the same structure have been prepared, and the MEL curves of the devices have been measured. It is found that there are neither TTAs nor RISC processes inside the devices at room temperature. Only at 20 K at low temperature and at high current can the TTA process occur. The cathode with lower power function is used to treat the anode with ozone O _ 3, and even increases the injection current of the device in an order of magnitude, which is beneficial to the realization of the TTA process. However, TTAs have not been observed. The experimental results of magnetoconductance and their theoretical simulations indicate that the interaction between triplet excitons and hole polarons may occur in the system. 鈫戔啈) P ~ (. 鈫，

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