High-efficiency circularly polarized emission from liquid-crystalline platinum complexes  

作　　者：Peng Fan Zhou Fang Shengyue Wang Qiwei Dong Chen Xiao Alice J.McEllin Duncan W.Bruce Weiguo Zhu Yafei Wang 

机构地区：[1]Jiangsu Key Laboratory of Environmentally Friendly Polymeric Materials,Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering,Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications,School of Materials Science&Engineering,Changzhou University,Changzhou 213164,China [2]Department of Chemistry,University of York,York YO105DD,United Kingdom [3]Anhui Sholon New Material Technology Co.,Ltd.,Chuzhou 239500,China

出　　处：《Chinese Chemical Letters》2023年第6期310-314,共5页中国化学快报（英文版）

基　　金：from the National Natural Science Foundation of China(Nos.51773021,51911530197,51473140);the Royal Society(IEC/NSFC/181139);the National Natural Science Foundation of China(Nos.51911530197 and 51773021)for an International Exchange Award(D.W.Bruce and Y.Wang);Six Talent Peaks Project in Jiangsu Province(No.XCL-102);Natural Science Fund for Colleges and Universities in Jiangsu Province(No.19KJA430002);Key technological tasks in Anhui Province(No.JB20007)。

摘　　要：Realizing both a high emission efficiency and luminescence dissymmetry factor(g_(lum))in circularly polarized solution processable organic light-emitting diodes(CP-OLEDs)remains a significant challenge.In this contribution,two chiral phosphorescent liquid crystals based on cyclometalated platinum complexes are prepared,in which the chiral s-2-methyl-1-butyl group is introduced into the cyclometalating ligand and the mesogenic fragment is attached to the periphery of the ancillary ligand.The platinum complexes exhibit both smectic and chiral nematic phases as evidenced by polarized optical microscopy,differential scanning calorimetry and small-angle X-ray diffraction.Remarkably,a high photoluminescent quantum efficiency of over 78%and clear circularly polarized luminescent signal with g_(PL)of about 10^(-2)are observed for the complexes.Further,solution-processed CP-OLEDs show maximum external quantum efficiencies(EQE)of over 15%and strong circularly polarized electroluminescent signals with a g_(EL)≈10^(-2).This research demonstrates that both liquid crystallinity and the number of chiral centers play key roles in improving the chiroptical property,paving the way for a new approach for the design of high-efficiency CPL emitters.

关 键 词：Circularly polarized emission LIQUID-CRYSTALLINE Platinum complex Organic light-emitting diodes 

分 类 号：TN383.1[电子电信—物理电子学] O641.4[理学—物理化学]