Boron-based compounds exhibiting a multiresonance thermally activated delayed fluorescence are regarded promising as a narrowband blue emitter desired for efficient displays with wide color gamut. However, their planar nature makes them prone to concentration-induced excimer formation that broadens the emission spectrum, making it hard to increase the emitter concentration without raising CIE y coordinate. To overcome this bottleneck, we here propose o -Tol-ν-DABNA-Me, wherein sterically hindered peripheral phenyl groups are introduced to reduce intermolecular interactions, leading to excimer formation and thus making the pure narrowband emission character far less sensitive to concentration. With this approach, we demonstrate deep-blue OLEDs with y of 0.12 and full width at half maximum of 18 nm, with maximum external quantum efficiency (EQE) of ca. 33%. Adopting a hyperfluorescent architecture, the OLED performance is further enhanced to EQE of 35.4%, with mitigated efficiency roll-off, illustrating the immense potential of the proposed method for energy-efficient deep-blue OLEDs.

中文翻译：

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迈向高效深蓝色 OLED：定制多共振诱导的 TADF 分子以抑制准分子形成和接近一致的水平偶极子比

表现出多共振热激活延迟荧光的硼基化合物被认为是有前途的窄带蓝色发射体，可用于宽色域的高效显示器。然而，它们的平面性质使它们易于形成浓度诱导的准分子，从而拓宽发射光谱，因此很难在不提高 CIE 的情况下增加发射极浓度y协调。为了克服这个瓶颈，我们在这里提出哦-Tol-ν-DABNA-Me，其中引入空间位阻的外围苯基以减少分子间相互作用，导致准分子形成，从而使纯窄带发射特性对浓度不太敏感。通过这种方法，我们展示了深蓝色 OLEDy0.12 的半峰全宽为 18 nm，最大外量子效率 (EQE) 约为 0.12。33%。采用超荧光架构，OLED 性能进一步增强至 35.4% 的 EQE，同时减缓了效率滚降，说明了所提出的节能深蓝色 OLED 方法的巨大潜力。