Intramolecular Hydrogen‐Bonding‐Rigidified Boron‐Dipyrromethene Dimers for Narrowband Near‐Infrared OLEDs
Xia Suo, Zhihai Yang, Guo‐Xi Yang, Ruicheng Wang, Yueyan Zhang, Zafar Mahmood, Yanping Huo, Shi‐Jian Su, Shaomin JiABSTRACT
Narrowband organic light‐emitting diodes (OLEDs) have attracted growing interest, with remarkable progress achieved in the blue/green/red spectral regions. In contrast, realizing narrowband near‐infrared (NIR) OLEDs remains both crucial and challenging. In this work, we present a class of narrowband NIR fluorescent emitters featuring dual boron‐dipyrromethene (BODIPY) cores, reinforced by a hydrogen‐bonding‐locked strategy to achieve spectral purity. The proposed strategy increases molecular rigidity and narrows the full‐width at half‐maximum (FWHM) by suppressing stretching/scissoring vibrations. The proof‐of‐concept emitter αα‐BDP 2 exhibits narrowband NIR emission centered at 713 nm with a FWHM of only 31 nm (0.076 eV), while ββ‐BDP 2 achieves an exceptionally high photoluminescence quantum yield (PLQY) of 98% in toluene solution. By employing the developed BODIPY‐derived materials as terminal emitters, solution‐processed narrowband NIR OLEDs have been assembled with external quantum efficiency as high as 2.7% at 713 nm with FWHM of 55 nm. This work, according to the knowledge, represents one of the best instances of solution‐processed narrowband NIR OLEDs based on typical fluorescent emitters.