Analysis of exciton annihilation in high-efficiency sky-blue organic light-emitting diodes with thermally activated delayed fluorescence
Analysis of exciton annihilation in high-efficiency sky-blue organic light-emitting diodes with thermally activated delayed fluorescence
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DOI：
10.1016/j.orgel.2013.07.010
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发表时间：
2013-11-01
影响因子：
3.2
通讯作者：
Adachi, Chihaya
中科院分区：
文献类型：
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作者：
Masui, Kensuke;Nakanotani, Hajime;Adachi, Chihaya
我们使用 4,5-二 (9H-咔唑-9-基) 邻苯二甲腈 (2CzPN) 的热激活延迟荧光 (TADF) 研究有机发光二极管 (OLED) 中的外部量子效率 (eta(EQE)) 滚降。利用光学分析中的 2CzPN 分子内速率常数，我们构建了包含系间窜越和反向系间窜越的激子猝灭模型。该模型表明，由于 2CzPN 三重态寿命相对较长（273 μs），单重态-三重态湮灭和三重态-三重态湮灭主导了 eta(EQE) 滚降。这项工作提出了一种缓解基于 TADF 的 OLED 中激子猝灭过程的方法。 (C) 2013 Elsevier B.V. 保留所有权利。
We study external quantum efficiency (eta(EQE)) roll-off in organic light-emitting diodes (OLEDs) using thermally-activated delayed fluorescence (TADF) of 4,5-di (9H-carbazol-9-yl) phthalonitrile (2CzPN). Using 2CzPN intramolecular rate constants from optical analyses, we construct an exciton quenching model incorporating intersystem crossing and reverse intersystem crossing. The model indicates that singlet-triplet annihilation and triplet-triplet annihilation dominate eta(EQE) roll-off because of the relatively long 2CzPN triplet lifetime of 273 mu s. This work yields a method to relax the exciton quenching process in TADF based OLEDs. (C) 2013 Elsevier B. V. All rights reserved.