Considering the essential role of intramolecular interactions in engineering the photophysical properties of thermally activated delayed fluorescent (TADF) materials for organic light-emitting diode (OLED) applications, we designed and synthesized three blue TADF molecules using benzophenone, 2-benzoylpyridine, and 3-benzoylpyridine as acceptors and 3,6-di-tert-butylcarbazole as a donor, which were denoted as BTC, B2-TC, and B3-TC, respectively. H-bonding was introduced between the benzene and pyridine of 2-benzoylpyridine for B2-TC and between the donor and acceptor for B3-TC. The formation of intramolecular H-bonds greatly increased oscillator strength and simultaneously decreased the energy gap between the lowest singlet and triplet states, thus accelerating reverse intersystem crossing. Owing to this, the OLED employing B2-TC as an emitter achieved a maximum current efficiency of 51.6 cd A⁻¹ and a maximum external quantum efficiency of 25.1% with the electroluminescent peak at 480 nm. Thus, our work demonstrates an effective method to design blue TADF materials for high-performance OLEDs.

中文翻译：

---

使用具有快速反向系间窜越的热激活延迟荧光（TADF）材料实现高效有机发光二极管

考虑到分子内相互作用在有机发光二极管（OLED）应用的热激活延迟荧光（TADF）材料的光物理性质工程中的重要作用，我们使用二苯甲酮、2-苯甲酰吡啶和3-设计并合成了三种蓝色TADF分子。苯甲酰吡啶作为受体，3,6-二叔丁基咔唑作为供体，分别记为BTC、B2-TC和B3-TC。B2-TC的 2-苯甲酰吡啶的苯和吡啶之间引入氢键，B3-TC的供体和受体之间引入氢键。分子内氢键的形成大大增加了振荡强度，同时减小了最低单重态和三重态之间的能隙，从而加速了反向系间窜越。由此，采用B2-TC作为发射极的OLED实现了51.6cd A ^-1的最大电流效率和25.1%的最大外量子效率，电致发光峰值在480 nm处。因此，我们的工作展示了一种设计用于高性能 OLED 的蓝色 TADF 材料的有效方法。