Hui Yun Ju, Lim Junseop, Yeob Lee Jun, Lee Yoonkyoo, Chu Changwoong
School of Chemical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do, 16419, Korea.
Display Research Center, Samsung Display Co., 1 Samsung-ro, Giheung-gu, Yongin, Gyeonggi-do, Korea.
Chemistry. 2021 Sep 1;27(49):12642-12648. doi: 10.1002/chem.202101819. Epub 2021 Jul 30.
A thermally activated delayed fluorescence (TADF)-type exciplex host employing a novel electron-transport type (n-type) type host managing positive polarons and stabilizing excitons was developed to elongate the device lifetime of deep blue phosphorescent organic light-emitting diodes (PhOLEDs). The bipolar n-type host was designed to prevent hole leakage and secure hole stability while being stabilized under excitons by introducing a CN-modified carbazole moiety as a weak donor. The TADF-type exciplex host-based blue PhOLEDs showed high (above 20 %) quantum efficiency with a deep blue color coordinate of (0.14, 0.16) and elongated device lifetime. The device operational lifetime of the blue PhOLEDs bearing the TADF-type exciplex host was extended by more than twice compared to that of the exciplex-free unipolar host. This work suggested a design concept of the n-type host to develop the TADF-type exciplex host for deep blue phosphors to reach a long lifespan in the deep blue PhOLEDs.
为了延长深蓝色磷光有机发光二极管（PhOLED）的器件寿命，开发了一种热激活延迟荧光（TADF）型激基复合物主体，该主体采用了一种新型的电子传输型（n型）主体，用于管理正极化子并稳定激子。通过引入作为弱供体的CN修饰咔唑部分，设计了双极性n型主体，以防止空穴泄漏并确保空穴稳定性，同时在激子作用下保持稳定。基于TADF型激基复合物主体的蓝色PhOLED显示出高（超过20%）的量子效率，色坐标为深蓝色（0.14, 0.16），并且器件寿命得以延长。与无激基复合物的单极性主体相比，带有TADF型激基复合物主体的蓝色PhOLED的器件工作寿命延长了两倍多。这项工作提出了一种n型主体的设计概念，以开发用于深蓝色磷光体的TADF型激基复合物主体，从而在深蓝色PhOLED中实现长寿命。
