Two-channel emission controlled by a conjugation valve for the color switching of thermally activated delayed fluorescence emission
作者:Rajendra Kumar Konidena、Kyung Hyung Lee、Jun Yeob Lee
DOI:10.1039/c9tc02618e
日期:——
of two-channel emission featuring deep-blue thermally activated delayed fluorescent (TADF) emitters is highly challenging due to their unavoidably extended conjugated structures. Herein, we propose a simple and effective strategy involving engineering of the interconnection position and formation of a “conjugation valve” to control their emission colors, including enabling emission of deep-blue light
由于深蓝色热激活延迟荧光(TADF)发射器的两通道发射技术不可避免地扩展了共轭结构,因此具有很大的挑战性。本文中,我们提出了一种简单有效的策略,其中涉及互连位置的工程设计和“共轭阀”的形成,以控制其发射颜色,包括能够以不受影响的外部量子效率(EQE)发射深蓝色光。两个新型TADF发射体,即2,3',4,5'-四(9 H-咔唑-9-基)-[1,1'-联苯] -3,4'-二腈(34CzBN)和3,3 ′,5,5'-四(9 H-咔唑-9-基)-[1,1'-联苯] -4,4'-二腈(44CzBN),通过以两种不同的方式直接连接两个相同的TADF单元以产生不同的共轭程度来产生两条通道的发射路径。与同分异构体44CzBN相比,34CzBN的非共轭连接方式在中央核心产生严重的空间位阻,从而中断了广泛的共轭,并导致吸收和发射的蓝移明显。两通道发射过程的EQE比单通道发射过程高四倍。基于34CzBN的T