The benzofurocarbazole moieties are well-known donor moiety for the design of the thermally activated delayed fluorescence (TADF) emitters. However, only 5H-benzofuro[3,2-c]carbazole (34BFCz) was reported and no other benzofurocarbazole derivatives were covered in the literature. Herein, two benzofurocarbazole moieties, 12H-benzofuro[3,2-a]carbazole (12BFCz) and 7H-benzofuro[2,3-b]carbazole (23BFCz) were synthesized to investigate the effect of donor structure on photophysics and device parameters of TADF emitters. Two benzofurocarbazole derived TADF emitters, 12-(2-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-12H-benzofuro[3,2-a]carbazole (o12BFCzTrz) and 7-(2-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-7H-benzofuro[2,3-b]carbazole (o23BFCzTrz), were compared with 5-(2-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-5H-benzofuro[3,2-c]carbazole (oBFCzTrz). The benzofurocarbazole donor structure governed the TADF characteristics such as charge transfer property and emission color. The 12BFCz donor was effective to blue-shift the emission color and 34BFCz was useful to improve the EQE. The 12BFCz derived o12BFCzTrz showed blue-shifted color coordinate of (0.159, 0.288) compared to (0.178, 0388) of o23BFCzTrz and (0.169, 0.341) of oBFCzTrz. The 34BFCz derived oBFCzTrz exhibited EQE of 22.9% compared to 19.2% of o12BFCzTrz and 21.1% of o23BFCzTrz.

中文翻译：

---

异构苯并呋喃咔唑供体的分子工程学，用于热激活延迟荧光发射体的光物理管理。

苯并呋喃咔唑部分是用于设计热活化延迟荧光（TADF）发射体的众所周知的供体部分。但是，仅报道了5H-苯并呋喃[3,2-c]咔唑（34BFCz），文献中未涵盖其他苯并呋喃咔唑衍生物。本文中，合成了两个苯并呋喃咔唑部分，分别是12H-苯并呋喃[3,2-a]咔唑（12BFCz）和7H-苯并呋喃[2,3-b]咔唑（23BFCz），以研究供体结构对苯并呋喃咔唑的光物理性质和器件参数的影响TADF发射器。两个苯并呋喃咔唑衍生的TADF发光体，12-（2-（4,6-diphenyl-1,3,5-triazin-2-yl）phenyl）-12H-苯并呋喃[3,2-a]咔唑（o12BFCzTrz）和7-将（2-（4,6-二苯基-1,3,5-三嗪-2-基）苯基）-7H-苯并呋喃[2,3-b]咔唑（o23BFCzTrz）与5-（2-（4 1,6-二苯基-1,3,5-三嗪-2-基）苯基）-5H-苯并呋喃[3,2-c]咔唑（oBFCzTrz）。苯并呋喃咔唑的给体结构决定着TADF的特性，如电荷转移性质和发射颜色。12BFCz供体可有效使发射颜色蓝移，而34BFCz可用于改善EQE。与o23BFCzTrz的（0.178，0388）和oBFCzTrz的（0.169，0.341）相比，12BFCz派生的o12BFCzTrz显示了（0.159，0.288）的蓝移颜色坐标。源自34BFCz的oBFCzTrz的EQE为22.9％，而o12BFCzTrz的19.2％和o23BFCzTrz的21.1％。169，0.341）的oBFCzTrz。源自34BFCz的oBFCzTrz的EQE为22.9％，而o12BFCzTrz的19.2％和o23BFCzTrz的21.1％。169，0.341）的oBFCzTrz。源自34BFCz的oBFCzTrz的EQE为22.9％，而o12BFCzTrz的19.2％和o23BFCzTrz的21.1％。