Revealing the Evolution Processes of Excitons on High Energy Level in Anthracene-Based OLEDs
Revealing the Evolution Processes of Excitons on High Energy Level in Anthracene-Based OLEDs
复制标题
DOI：
10.1002/adfm.202207123
复制
发表时间：
2022-08-20
影响因子：
19
通讯作者：
Ma，Dongge
中科院分区：
文献类型：
--
作者：
Xiao，Shu;Qiao，Xianfeng;Ma，Dongge
众所周知，电产生的激子可以在高激发态之间进行自旋演化，这为在有机发光二极管（OLED）中利用三重态激子提供了一种有效的方法。蒽家族提供了一个深入研究三重态激子在高激发态上的详细过程的机会。在这里，提出了一个简化模型来研究基于蒽衍生物的器件中的激子动力学。通过理论计算、瞬态电致发光、瞬态光致发光和瞬态吸收光谱测量，很好地揭示了蒽衍生物高能级系间交叉过程的机制。此外，还提出了抑制激子损耗通道的掺杂策略，以提高器件的效率。这些研究建立了一种原位方法来评估由于高激发态之间的激子演化而导致的器件中的表观单重态激子形成率，并为进一步利用这些三重态激子提供了一些线索，从而提高了未来所得荧光OLED的效率。
It is well‐known that the electrically generated excitons can perform the spin evolution between high‐lying excited states, providing an efficient way to utilize triplet excitons in organic light‐emitting diodes (OLEDs). Anthracene families offer an opportunity to deeply investigate the processes of triplet excitons on high‐lying excited states in detail. Here, a simplified model is proposed to study the exciton dynamics in anthracene derivatives‐based devices. The mechanism on the processes of high‐energy level intersystem crossing in anthracene derivatives is well revealed by theoretical calculation, transient electroluminescence, transient photoluminescence, and transient absorption spectrum measurements. Besides, doping strategy is proposed to suppress the exciton loss channel for improving the efficiency of devices. The studies establish an in situ method to evaluate the apparent singlet exciton formation ratio in devices due to the exciton evolution between high‐lying excited states and offer some clues to further utilize these triplet excitons, thus improving the efficiency of the resulting fluorescence OLEDs in the future.