125th General Meeting of the KCS

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Type Oral Presentation
Area Oral Presentation for Young Material Chemists
Room No. Room 303 (Live Streaming)
Time TUE 09:15-09:30
Code MAT.O-2
Subject Deep-Red to NIR Emission and Aggregation-Induced Enhancement of Iridium(III) Complexes for Solution-Processable OLEDs
Authors Hae Un Kim, Sungjin Park, Taehyun Kim, Taiho Park*
Department of Chemical Engineering, Pohang University of Science and Technology, Korea
Abstract To fight against the counteractive triplet–triplet annihilation and vibrational deactivation faced by low bandgap phosphorescent emitters, aggregation-induced phosphorescent enhancement (AIPE)-active deep-red and NIR emissive iridium(III) complexes are designed by suitably anchoring electron-withdrawing substituents such as -phenyl (Ir2), -ethyl ester (Ir3), and -trifluoromethyl (Ir4) groups on the N-coordinating quinoline moiety of a cyclometalated ligand along with ancillary picolinate. The fundamentals of the origin of AIPE on Ir2 and Ir4 and its associated excited-state properties are deeply studied through comparison with unsubstituted Ir1 with the help of density functional theory and single-crystal X-ray diffraction analysis. Most importantly, AIPE-active Ir2 is employed for the development of efficient deep-red and NIR PhOLEDs by hybrid solution-processable methods, in which the AIPE effect of Ir2 reaches a maximum external quantum efficiency (EQE) of 7.3% at high doping ratios.
E-mail hukim@postech.ac.kr