BP-mDTC (75%) plausibly due to the more rigid structure caused by the interaction between pyridine nitrogen and the aromatic C–H bond. Furthermore, 4BPy-mDTC shows a more delayed component compared to 3BPy-mDTC and 2BPy-mDTC. The electroluminescent devices based on 4BPy-mDTC and 2BPy-mDTC as the dopant emitters exhibit sky blue emission with maximum external quantum efficiencies (EQEs) over 28%, and
热激活延迟荧光(TADF)发射器对于显示和照明应用很有吸引力。在这里,一系列高效的蓝色TADF发射体包括3,5-双((3,6-二叔丁基-9 H-
咔唑-9-基)苯基)(
吡啶-4-基)甲酮(4BPy- m DTC),(3,5-双(3,6-二叔丁基-9 H-
咔唑-9-基)苯基)(
吡啶-3-基)甲酮(3BPy- m DTC),(3, 5-双(3,6-二叔丁基-9 H-
咔唑-9-基)苯基)(
吡啶-2-基)甲酮(2BPy- m DTC)和(3,5-双(3,6 -二-叔丁基-9 H-
咔唑-9-基)苯基)(苯基)甲酮(BP- mDTC)被设计和合成。分子结构的特征是两个间
咔唑取代基与苯甲酰基
吡啶(BPy)基团或
二苯甲酮(BP)基团连接。这些化合物显示出高的热稳定性(T d = 371–439°C),蓝色发射(458–488 nm),薄膜中的高光致发光量子产率(PLQY)(75–96%)和S 1之间的非常小的能隙T