Thermally Activated Delayed Fluorescent Donor-Acceptor-Donor Acceptor π-Conjugated Macrocycle for Organic Light-Emitting Diodes
Thermally Activated Delayed Fluorescent Donor-Acceptor-Donor Acceptor π-Conjugated Macrocycle for Organic Light-Emitting Diodes
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DOI：
10.1021/jacs.9b11578
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发表时间：
2020-01-22
影响因子：
15
通讯作者：
Minakata, Satoshi
中科院分区：
文献类型：
--
作者：
Izumi, Saika;Higginbotham, Heather F.;Minakata, Satoshi
设计并合成了一类由两个U型电子受体（二苯并[a，j]吩嗪）和两个电子给体（N，N ′-二苯基对苯二胺）组成的热激活延迟荧光给体-受体-给体-受体（D-A-D-A）π共轭大环.该大环化合物显示出多晶型依赖的构象和发射性质。大环与线性替代物的物理化学性质的比较研究揭示了D-A重复单元的结构环化的显著影响，包括更有效的热活化延迟荧光（TADF）。此外，用大环化合物作为发光体制备的有机发光二极管（OLED）器件实现了高达11.6%的高外量子效率（EQE），远远超过传统荧光发光体的理论最大值（5%）和线性类似物的理论最大值（6.9%）。
A new class of thermally activated delayed fluorescent donor-acceptor-donor-acceptor (D-A-D-A) pi-conjugated macrocycle comprised of two U-shaped electron-acceptors (dibenzo[a,j]phenazine) and two electron-donors (N,N'-diphenyl-p-phenyelendiamine) has been rationally designed and successfully synthesized. The macrocyclic compound displayed polymorphs-dependent conformations and emission properties. Comparative studies on physicochemical properties of the macrocycle with a linear surrogate have revealed significant effects of the structural cyclization of the D-A-repeating unit, including more efficient thermally activated delayed fluorescence (TADF). Furthermore, an organic light-emitting diode (OLED) device fabricated with the macrocycle compound as the emitter has achieved a high external quantum efficiency (EQE) up to 11.6%, far exceeding the theoretical maximum (5%) of conventional fluorescent emitters and that with linear analogue (6.9%).