Department of Chemistry, Jilin University, State Key Laboratory of Supramolecular Structure and Materials, 2699 Qianjin Avenue, Changchun, 130012, P. R. China.
Department of Gynecologic Oncologic, the First Hospital of Jilin University, Changchun, 130021, P. R. China.
Chem Asian J. 2019 Mar 15;14(6):821-827. doi: 10.1002/asia.201801578. Epub 2018 Dec 17.
Red emission is one of the three primary colors that are essential for the realization of full-color displays and solid-state lightings. A high solid-state efficiency is a crucial factor for the applications in organic light-emitting diodes (OLEDs). In this work, two new donor-acceptor-donor type phenanthro[9,10-d]imidazole (PIM)-based derivatives, (2Z,2'Z)-2,2'-(1,4-phenylene)bis(3-(4-(1-phenyl-1H-phenanthro[9,10-d]imidazol-2-yl)phenyl)acrylonitrile) (PIDSB) and 2,3-bis(4'-(1-phenyl-1H-phenanthro[9,10-d]imidazol-2-yl)-[1,1'-biphenyl]-4-yl)fumaronitrile (PIDPh), are designed and synthesized. Both of them possess high thermal stabilities. PIDPh shows typical characteristics of aggregation-induced emission enhancement, while PIDSB displays an aggregation-caused quenching effect. They both exhibit significant red-shifted emissions compared with PIM owing to intramolecular charge transfer. In the film state, the emission peaks of PIDSB and PIDPh are located at 538 nm and 605 nm with high photoluminescent quantum yields of 63.82 % and 41.26 %, respectively. The non-doped OLED using PIDPh as the active layer shows the maximum external quantum efficiency of 2.06 % with a very low efficiency roll-off, and exhibits the electroluminescent peak at 640 nm with a Commission Internationale de l'Éclairage coordinate of (0.617,0.396), meeting well the criteria of red OLEDs.
红色发射光是实现全彩显示和固态照明所必需的三基色之一。高固态效率是有机发光二极管（OLED）应用的关键因素。在这项工作中，设计并合成了两种新型给体-受体-给体型菲并[9,10-d]咪唑（PIM）基衍生物，（2Z,2'Z）-2,2'-(1,4-亚苯基)双(3-(4-(1-苯基-1H-菲并[9,10-d]咪唑-2-基)苯基)丙烯腈)（PIDSB）和 2,3-双(4'-(1-苯基-1H-菲并[9,10-d]咪唑-2-基)-[1,1'-联苯]-4-基)马来腈（PIDPh）。它们都具有较高的热稳定性。PIDPh 表现出典型的聚集诱导发射增强特征，而 PIDSB 则表现出聚集导致的猝灭效应。与 PIM 相比，它们都显示出明显的红移发射，这是由于分子内电荷转移所致。在薄膜状态下，PIDSB 和 PIDPh 的发射峰分别位于 538nm 和 605nm，光致发光量子产率分别高达 63.82%和 41.26%。以 PIDPh 为发光层的非掺杂 OLED 显示出 2.06%的最大外量子效率，效率滚降很小，其电致发光峰位于 640nm，国际照明委员会坐标为（0.617,0.396），很好地满足了红色 OLED 的标准。
