Li Xiang, Yuan Peng, Song Jinyu, Chang Yu, Jiao Xueting, Zhao Jianfen, Zhang Cong, Li Wenjuan, Hang Xiao-Chun
School of Flexible Electronics (Future Technologies), Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China.
Nanjing Jianuolin Optoelectronics Technology Co., Ltd., 5th Xin Mofan Road, Nanjing 210009, China.
Molecules. 2023 Jun 29;28(13):5118. doi: 10.3390/molecules28135118.
In organic light-emitting diodes, positive and negative charge carriers mostly migrate at different rates. This could result in excitons formed in the EML often migrating to the vicinity of the hole transport layer and the electron transport layer. To address this, it is important to design high-quality multi-resonance hosts that can balance the migration rate of carriers. Here, we report two newly developed multi-resonance hosts, m-ICzPBI and o-ICzPBI. The hosts contain an indolo[3,2,1-]carbazole (ICz) motif, which functionalized as either a donor or an acceptor unit. The hosts exhibit extremely high molecular rigidity and thermal stability. Devices A and B were constructed using FIrpic as a phosphorescent emitter with m-ICzPBI or o-ICzPBI as a host. Device A achieved high maximum values of EQE, PE and CE of 13.4%, 24.8 lm W and 31.6 cd A, respectively, and low efficiency roll-off at 5000 cd m of 8.6%, 10.6 lm W and 20.3 cd A, respectively.
在有机发光二极管中，正电荷载流子和负电荷载流子的迁移速率大多不同。这可能导致在发射层（EML）中形成的激子经常迁移到空穴传输层和电子传输层附近。为了解决这个问题，设计能够平衡载流子迁移速率的高质量多共振主体非常重要。在此，我们报告了两种新开发的多共振主体，即间位-吲哚并[3,2,1-cd]咔唑-1,3,5-三嗪（m-ICzPBI）和邻位-吲哚并[3,2,1-cd]咔唑-1,3,5-三嗪（o-ICzPBI）。这些主体包含一个吲哚并[3,2,1-cd]咔唑（ICz）基团，其可作为供体或受体单元进行功能化。这些主体表现出极高的分子刚性和热稳定性。器件A和器件B以双（4,6-二氟苯基吡啶-N,C2′）-吡啶甲酰合铱（FIrpic）作为磷光发射体，以m-ICzPBI或o-ICzPBI作为主体构建而成。器件A分别实现了13.4%、24.8流明/瓦和31.6坎德拉/安培的高外量子效率（EQE）、功率效率（PE）和电流效率（CE）最大值，以及在5000坎德拉/平方米时分别为8.6%、10.6流明/瓦和20.3坎德拉/安培的低效率滚降。
