Enhancing Reverse Intersystem Crossing via Secondary Acceptors: toward Sky-Blue Fluorescent Diodes with 10-Fold Improved External Quantum Efficiency
Enhancing Reverse Intersystem Crossing via Secondary Acceptors: toward Sky-Blue Fluorescent Diodes with 10-Fold Improved External Quantum Efficiency
复制标题
通过次级受体增强反向系间穿越：实现外部量子效率提高 10 倍的天蓝色荧光二极管
DOI：
10.1021/acsami.8b18041
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发表时间：
2019
影响因子：
9.5
通讯作者：
Xu Hui
中科院分区：
文献类型：
--
作者：
Fang Xuefeng;Li Chenyu;Wang Zicheng;Wei Ying;Duan Chunbo;Han Chunmiao;Xu Hui
如何简单而有效地促进反向系统间穿越（RISC）跃迁一直是开发高性能热激活延迟荧光染料的关键问题。在这项工作中，作为一个概念的证明，一个可行的策略命名为“受体增强”，证明了一系列的三元蓝色发光体（xCzmPOnTPTZ）使用二苯基氧化膦（PO）作为二级受体。与其无PO的二元类似物相比，在pCzPO2TPTZ中如此简单地引入PO基团使其RISC速率常数（kRISC）显著提高了10倍，RISC效率（ηRISC）为92%，这进一步提高了其器件中有效三重态收获的三重态到单重态的上转换。结果，在三层器件结构的基础上，pCzPO 2 TPTZ实现了超过20%的最先进的外部量子效率，具有10倍的改进。
How to simply but effectively facilitate reverse intersystem crossing (RISC) transition is always the key issue for developing high-performance thermally activated delayed fluorescence dyes. In this work, as a proof of concept, a feasible strategy named “acceptor enhancement” is demonstrated with a series of ternary blue emitters (xCzmPOnTPTZ) using diphenylphosphine oxide (PO) as secondary acceptors. Compared with its PO-free binary analogue, such a simple introduction of PO groups inpCzPO2TPTZdramatically enhances its RISC rate constant (kRISC) by 10 times the level of ∼105s–1, accompanied by RISC efficiency (ηRISC) of 92%, which further improves the triplet-to-singlet upconversion for effective triplet harvesting in its devices. As a result, on the basis of a trilayer device structure,pCzPO2TPTZrealized a state-of-the-art external quantum efficiency beyond 20% with a 10-fold improvement.