Developing high-efficiency nondoped blue organic light-emitting diodes (OLEDs) with high color purity and low-efficiency roll-off is vital for display and lighting applications. Herein, we developed two asymmetric D-π–A blue emitters, PIAnTP and PyIAnTP, in which triphenylene is first utilized as a functional acceptor. The relatively weak charge transfer (CT) properties, rigid molecular structures, and multiple supramolecular interactions in PIAnTP and PyIAnTP can significantly enhance the fluorescence efficiency and suppress the structural relaxations to obtain a narrowband blue emission. The photophysical experiments and theoretical simulations reveal that they both exhibit a typical hybridized local and charge-transfer (HLCT) excited state and achieve high external quantum efficiency (EQE) via a “hot exciton” channel. As a result, PIAnTP- and PyIAnTP-based nondoped devices realize blue emission at 456 and 464 nm, corresponding to CIE coordinates of (0.16, 0.14) and (0.16, 0.19), narrow full width at half-maximums of 52 and 60 nm, and the high EQEs of 8.36 and 8.69%, respectively. More importantly, the PIAnTP- and PyIAnTP-based nondoped devices show small EQE roll-offs of only 5.9 and 2.4% at 1000 cd m^–2, respectively. These results signify an advance in designing a highly efficient blue emitter for nondoped OLEDs.

中文翻译：

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具有混合局部和电荷转移特性的苯并菲基发射体，用于具有窄带发射和小效率滚降的高效非掺杂蓝色 OLED

开发具有高色纯度和低效率滚降的高效非掺杂蓝色有机发光二极管 (OLED) 对于显示和照明应用至关重要。在此，我们开发了两种不对称的D-π-A蓝色发射体PIAnTP和PyIAnTP，其中苯并菲首先被用作功能受体。PIAnTP和PyIAnTP相对较弱的电荷转移（CT）特性、刚性的分子结构和多重超分子相互作用可以显着提高荧光效率并抑制结构弛豫，从而获得窄带蓝色发射。光物理实验和理论模拟表明，它们都表现出典型的混合局部和电荷转移（HLCT）激发态，并通过“热激子”通道实现高外量子效率（EQE）。结果，基于PIAnTP和PyIAnTP的非掺杂器件实现了456和464 nm的蓝色发射，对应于CIE坐标（0.16，0.14）和（0.16，0.19），半峰全宽为52和60 nm ，EQE 分别高达 8.36 和 8.69%。^{更重要的是，基于 PIAnTP 和 PyIAnTP 的非掺杂器件在 1000 cd m –2}下表现出较小的 EQE 滚降，分别仅为 5.9% 和 2.4% 。这些结果标志着在设计用于非掺杂 OLED 的高效蓝色发射器方面取得了进展。