Abstract A lifetime extending molecular design approach by increasing the bond dissociation energy of the thermally activated delayed fluorescent (TADF) emitters was investigated. A TADF emitter with a molecular design having the donors in a planar manner, 4-(9H-carbazol-9-yl)-6-(9,9″-diphenyl-9H,9′H,9″H-[3,3′:6′,3″-tercarbazol]-9′-yl)isophthalonitrile (TCzIPN), was compared with state of the art green TADF emitter. The two emitters were green TADF emitters with similar peak wavelengths, but the TCzIPN exhibited three times longer lifetime than the current TADF emitter. Analysis of bond dissociation energy of the TADF emitters revealed that the weak C N bond of the TCzIPN was stabilized by small dihedral angle between donor and an aromatic linker. This was confirmed by exciton stability test of the emitters, and the C N bond stabilization effect in triplet excited state was well correlated with the lifetime improvement of the TCzIPN devices.

中文翻译：

---

通过增加激发态键解离能延长绿色热激活延迟荧光有机发光二极管的寿命

摘要 研究了通过增加热激活延迟荧光 (TADF) 发射体的键离解能来延长寿命的分子设计方法。具有分子设计的 TADF 发射体，具有平面方式的供体，4-(9H-carbazol-9-yl)-6-(9,9"-diphenyl-9H,9'H,9"H-[3, 3':6',3'-tercarbazol]-9'-yl)间苯二甲腈 (TCzIPN) 与最先进的绿色 TADF 发射器进行了比较。这两个发射器是具有相似峰值波长的绿色 TADF 发射器，但 TCzIPN 的使用寿命是当前 TADF 发射器的三倍。TADF 发射体的键解离能分析表明，TCzIPN 的弱 CN 键通过供体和芳族连接体之间的小二面角稳定。这通过发射器的激子稳定性测试得到证实，