The fabrication of deep-blue emitting materials with high color purity is crucial for the realization of ultra-high-definition display technology based on organic light-emitting diodes (UHD-OLEDs). However, the intrinsic broad-band emission of organic emitters makes this task difficult. In this study, 9,9-dimethyl-9,10-dihydroacridine (DMAC) was fused with an additional phenyl moiety to design rigid 12,12-dimethyl-7,12-dihydrobenzo[a]acridine (DMBA) as a novel chromophore for design of deep-blue narrow-band emission emitters. Furthermore, functionalization of DMBA with a cyano group yielded two bipolar emitters, viz. 12,12-dimethyl-7-phenyl-7,12-dihydrobenzo[a]acridine-3-carbonitrile (BACN) and 4-(12,12-dimethyl-7-phenyl-7,12-dihydrobenzo[a]acridin-3-yl)benzonitrile (BAPCN). The single-crystal structure analysis confirmed that BACN and BAPCN featured large rigid planar structures. The photophysical study demonstrated that both emitters exhibited narrow-band emissions in the deep-blue region with high fluorescence quantum efficiencies. The doped device based on BACN demonstrates an efficient deep-blue emission that peaks at 437 nm with a small full width at half maximum of 41 nm/0.26 eV and a corresponding Commission International de L’Eclairage (CIE) coordinate of (0.153, 0.049). Meanwhile, their non-doped devices show lower turn-on voltage and smaller external quantum efficiency (EQE) roll-off, particularly in the BAPCN-based non-doped device with a negligible EQE roll-off of only 4.4% at 10 000 cd m⁻², as a consequence of their good/balanced carrier transporting properties. The optoelectronic properties of these emitters substantiate their potential as deep-blue emitting materials for OLED applications.

中文翻译：

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新型 12,12-二甲基-7,12-二氢苯并[a]吖啶作为具有窄带发射和抑制效率滚降的 OLED 的深蓝色发光发色团

制造具有高色纯度的深蓝色发光材料对于实现基于有机发光二极管 (UHD-OLED) 的超高清显示技术至关重要。然而，有机发射体的固有宽带发射使这项任务变得困难。在这项研究中，9,9-二甲基-9,10-二氢吖啶（DMAC）与一个额外的苯基部分融合，设计出刚性的12,12-二甲基-7,12-二氢苯并[ a ]吖啶（DMBA）作为一种新型的发色团用于设计深蓝色窄带发射器。此外，带有氰基的 DMBA 官能化产生了两个双极发射体，即。12,12-二甲基-7-苯基-7,12-二氢苯并[ a ]吖啶-3-甲腈(BACN)和4-(12,12-二甲基-7-苯基-7,12-二氢苯并[ a]]吖啶-3-基）苄腈（BAPCN）。单晶结构分析证实 BACN 和 BAPCN 具有大的刚性平面结构。光物理研究表明，两种发射器都在深蓝色区域表现出窄带发射，具有高荧光量子效率。基于 BACN 的掺杂器件表现出有效的深蓝色发射，峰值为 437 nm，半峰全宽较小，为 41 nm/0.26 eV，相应的国际委员会 (CIE) 坐标为 (0.153, 0.049 ）。同时，他们的非掺杂器件显示出更低的开启电压和更小的外部量子效率 (EQE) 滚降，特别是在基于 BAPCN 的非掺杂器件中，在 10 000 cd 时的 EQE 滚降可以忽略不计，仅为 4.4%米^-2，由于其良好/平衡的载流子传输特性。这些发射器的光电特性证实了它们作为用于 OLED 应用的深蓝色发光材料的潜力。