Optimizing Charge Transfer and Out-Coupling of A Quasi-Planar Deep-Red TADF Emitter: towards Rec.2020 Gamut and External Quantum Efficiency beyond 30 %
Optimizing Charge Transfer and Out-Coupling of A Quasi-Planar Deep-Red TADF Emitter: towards Rec.2020 Gamut and External Quantum Efficiency beyond 30 %
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DOI：
10.1002/anie.202103070
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发表时间：
2021-05-24
影响因子：
16.6
通讯作者：
Xu, Hui
中科院分区：
文献类型：
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作者：
Li, Zhe;Yang, Dezhi;Xu, Hui
在此，我们报道了一种深红色TADF发射体pCNQ-TPA，由喹喔啉-5,8-二甲腈（pCNQ）受体和三苯胺（TPA）供体组成。 pCNQ-TPA 支持其 OLED 具有所需的 CIE 坐标 (0.69, 0.31) 和创纪录的 30.3% 的最大外部量子效率，这是适用于 UHDTV 的具有 Rec.2020 色域的最佳红色 TADF 二极管。结果表明，通过调节pCNQ-TPA掺杂浓度，平衡分子内和分子间电荷转移，同步提高发射颜色饱和度和TADF辐射，并纠正聚集引起的猝灭，使深红色发射峰值在约690 nm处的光致发光量子产率（PLQY）达到90%。准平面结构进一步赋予 pCNQ-TPA 更高的发射偶极子取向水平比，从而将光输出耦合比提高到 0.34，从而实现最先进的器件效率。
Herein, we report a deep-red TADF emitter pCNQ-TPA, composed of quinoxaline-5,8-dicarbonitrile (pCNQ) acceptor and triphenylamine (TPA) donor. pCNQ-TPA supported its OLED with desired CIE coordinates of (0.69, 0.31) and the record maximum external quantum efficiency of 30.3 %, which is the best red TADF diode with Rec.2020 gamut for UHDTV. It is showed that through tuning pCNQ-TPA doping concentration, intra- and inter-molecular charge transfer are balanced to synchronously improve emission color saturation and TADF radiation, and remedy aggregation-induced quenching, rendering photoluminescence quantum yield (PLQY) reaching 90 % for deep-red emission peaked at approximate to 690 nm. Quasi-planar structure further endows pCNQ-TPA with an improved horizontal ratio of emitting dipole orientation, which increases light out-coupling ratio to 0.34 for achieving the state-of-the-art device efficiencies.