Configurationally Stable Platinahelicene Enantiomers for Efficient Circularly Polarized Phosphorescent Organic Light-Emitting Diodes |
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| Authors: | Zhi-Ping Yan Xu-Feng Luo Wei-Qiang Liu Zheng-Guang Wu Xiao Liang Kang Liao Dr. Yi Wang Prof. You-Xuan Zheng Prof. Liang Zhou Prof. Jing-Lin Zuo Prof. Yi Pan Prof. Hongjie Zhang |
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| Affiliation: | 1. State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 P. R. China;2. State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022 P. R. China |
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| Abstract: | Chiral materials with circularly polarized luminescence (CPL) are potentially applicable for 3D displays. In this study, by decorating the pyridinyl-helicene ligands with -CF3 and -F groups, the platinahelicene enantiomers featured superior configurational stability, as well as high sublimation yield (>90 %) and clear CPPL properties, with dissymmetry factors (|gPL|) of approximately 3.7×10−3 in solution and about 4.1×10−3 in doped film. The evaporated circularly polarized phosphorescent organic light-emitting diodes (CP-PhOLEDs) with two enantiomers as emitters exhibited symmetric CPEL signals with |gEL| of (1.1–1.6)×10−3 and decent device performances, achieving a maximum brightness of 11 590 cd m−2, a maximum external quantum efficiency up to 18.81 %, which are the highest values among the reported devices based on chiral phosphorescent PtII complexes. To suppress the effect of reverse CPEL signal from the cathode reflection, the further implementation of semitransparent aluminum/silver cathode successfully boosts up the |gEL| by over three times to 5.1×10−3. |
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| Keywords: | chiral platinahelicene dissymmetry factor high efficiency OLEDs semitransparent device |
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