Feng Zhan, Weiwei Lou, Hongjian Zheng, Guijie Li, Yuanbin She
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引用次数: 0
Abstract
Tetra-coordinated fluoroboron compounds have garnered significant attention in organic light-emitting diodes (OLEDs) due to their remarkable optoelectronic properties and high chemical stability. However, the design of novel tetra-coordinated fluoroboron-based blue thermally activated delayed fluorescence (TADF) materials with excellent external quantum efficiency (EQE) remains crucial. In this study, a novel tetra-coordinated difluoroboron-based blue TADF material with 3,6-diphenylcarbazole donor and 2-(4-phenylpyridin-2-yl)phenolate difluoroboron acceptor molecular skeleton has been designed and synthesized. Benefiting from the larger dihedral angle (68.0°) between the donor and acceptor moieties, the compound m-PhCz-BF2 exhibited a smaller singlet-triplet energy splitting (ΔEST) value of 0.043 eV. As a result, a sky-blue emission with peak wavelengths of 491 and 487 nm and photoluminescence quantum yields (PLQY) of 93% and 99% were obtained in solution and doped film, respectively. Additionally, the m-PhCz-BF2 doped OLED demonstrated sky-blue electroluminescence (Commission Internationale de l’Éclairage, CIEy ⩽ 0.33) and a high peak EQE of 27.4% with maximum brightness of 17,493 cd/m2. Notably, these devices also achieved a high current efficiency of 62.5 cd/A and a power efficiency of 49.4 lm/W. These remarkable performances indicate that the m-PhCz-BF2 has the potential to function as a highly efficient TADF dopant for the fabrication of sky-blue OLEDs.
四配位氟硼化合物以其优异的光电性能和较高的化学稳定性在有机发光二极管中引起了广泛的关注。然而，具有优异外量子效率（EQE）的新型四配位氟硼基蓝色热激活延迟荧光（TADF）材料的设计仍然至关重要。本研究设计并合成了以3,6-二苯基咔唑为供体，2-（4-苯基吡啶-2-基）苯酚二氟硼为受体的新型四配位二氟硼蓝色TADF材料。化合物m-PhCz-BF2由于供体和受体之间的二面角较大（68.0°），单重态-三重态能量分裂值较小（ΔEST），为0.043 eV。结果表明，在溶液和掺杂薄膜中分别获得了峰值波长为491 nm和487 nm的天蓝色发射，光致发光量子产率（PLQY）分别为93%和99%。此外，m-PhCz-BF2掺杂的OLED表现出天蓝色电致发光（Commission Internationale de l ' Éclairage, CIEy≤0.33），峰值EQE为27.4%，最大亮度为17,493 cd/m2。值得注意的是，这些器件还实现了62.5 cd/ a的高电流效率和49.4 lm/W的功率效率。这些显著的性能表明，m-PhCz-BF2具有作为一种高效的TADF掺杂剂用于制造天蓝色oled的潜力。
期刊介绍：
Science China Chemistry, co-sponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China and published by Science China Press, publishes high-quality original research in both basic and applied chemistry. Indexed by Science Citation Index, it is a premier academic journal in the field.
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