Cui Dongyue, Zhang Longyan, Zhang Jingyu, Li Wenjing, Chen Jie, Guo Zhenli, Sun Chengxi, Wang Yike, Wang Wenjun, Li Shuhong, Huang Wei, Zheng Chao, Chen Runfeng
State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China.
Shandong Provincial Key Laboratory of Optical Communication Science and Technology, School of Physical Science and Information Technology, Liaocheng University, Shandong, 252059, China.
Angew Chem Int Ed Engl. 2024 Nov 4;63(45):e202411588. doi: 10.1002/anie.202411588. Epub 2024 Sep 12.
Organic ultralong room temperature phosphorescence (OURTP) materials capable of combining various emission behaviors for diversified optoelectronic properties and applications have recently gained a vigorous development, but it remains a forbidden challenge in designing OURTP molecules with hybrid local and charge-transfer (HLCT) feature, possibly due to the elevated difficulties in simultaneously meeting the stringent requirements of both HLCT and OURTP emitters. Here, through introducing multiple heteroatoms into one-dimensional fused ring of coumarin with moderate charge transfer perturbation in donor-π-acceptor architecture, we demonstrate a HLCT-featured OURTP molecule showing both promoted fluorescence with a quantum yield of 77 % in solution and long-lived OURTP with a lifetime of 251 ms in conventional host material used in electroluminescent device. Thus, efficient OURTP organic light-emitting diodes (OLEDs) were fabricated, exhibiting bright electroluminescence with an exciton utilization efficiency of 85 % and yellow OURTP lasting over 2 s for afterglow. Impressively, the HLCT OURTP-OLEDs can be further optimized to reach an unprecedented total external quantum efficiency (EQE) of ~12 % and OURTP EQE up to 3.11 %, representing the highest performance among the reported OURTP-OLEDs. These impressive results highlight the significance to fuse HLCT and OURTP together in enriching OURTP materials and improving the afterglow OLED performances.
能够结合各种发射行为以实现多样化光电特性和应用的有机超长室温磷光（OURTP）材料最近得到了蓬勃发展，但设计具有杂化局域和电荷转移（HLCT）特征的OURTP分子仍然是一个极具挑战性的难题，这可能是由于同时满足HLCT和OURTP发射体的严格要求难度增大所致。在此，通过在供体-π-受体结构中向香豆素的一维稠环引入多个杂原子，并进行适度的电荷转移扰动，我们展示了一种具有HLCT特征的OURTP分子，它在溶液中具有77%的量子产率，荧光得到增强，在用于电致发光器件的传统主体材料中具有251 ms的长寿命OURTP。因此，制备了高效的OURTP有机发光二极管（OLED），其表现出明亮的电致发光，激子利用效率为85%，黄色OURTP余辉持续超过2 s。令人印象深刻的是，HLCT OURTP-OLED可以进一步优化，达到前所未有的约12%的总外量子效率（EQE）和高达3.11%的OURTP EQE，代表了已报道的OURTP-OLED中的最高性能。这些令人印象深刻的结果凸显了将HLCT和OURTP融合在一起对于丰富OURTP材料和提高余辉OLED性能的重要性。
