Fused-ring compounds containing a N–B–N (NBN) unit have emerged as a class of emitters for organic light-emitting diodes (OLEDs) in recent years. However, despite the success of these compounds in achieving efficient green OLEDs, their application in blue OLEDs has not yet been realized. In this study, two new NBN-containing compounds featuring unsymmetrical molecular structures are designed and synthesized. The structural design endows the compounds with efficient blue emission and narrower emission bandwidths. A blue fluorescent OLED based on one of the compounds exhibits simultaneously a high external quantum efficiency of 4.2% and an excellent Commission Internationale de L'Eclairage (CIE) coordinate of (0.152, 0.096). The impressive performance of the OLED device suggests that with proper molecular designs, NBN-containing compounds possess great potential as excellent blue emitters for OLEDs, and thus merit further investigation and attention.

中文翻译：

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用于高效蓝色 OLED 的具有 N-B-N 单元的稠环化合物

近年来，含有 N-B-N (NBN) 单元的稠环化合物已成为有机发光二极管 (OLED) 的一类发射体。然而，尽管这些化合物成功实现了高效的绿色OLED，但它们在蓝色OLED中的应用尚未实现。在这项研究中，设计并合成了两种具有不对称分子结构的新型含NBN化合物。该结构设计赋予化合物高效的蓝光发射和更窄的发射带宽。基于其中一种化合物的蓝色荧光OLED同时表现出4.2％的高外量子效率和优异的国际照明委员会(CIE)坐标(0.152，0.096)。OLED器件令人印象深刻的性能表明，通过适当的分子设计，含NBN的化合物具有作为OLED优异的蓝色发射体的巨大潜力，因此值得进一步研究和关注。