120th General Meeting of the KCS

Type Poster Presentation
Area Industrial Chemistry
Room No. Exhibition Hall 2+3
Time 10월 20일 (금요일) 13:00~14:30
Code IND.P-69
Subject Detailed Investigation of Photophysical Properties of Isomeric Carbene Ir(III) Complexes and their Applications to Deep-blue Phosphorescent Organic Light Emitting Diodes
Authors JaeHyun Park, Yang-Jin Cho, So-Yoen Kim, Jin-Hyoung Kim, Won-Sik Han1, Sang Ook Kang, Ho-Jin Son*
Department of Advanced Materials Chemistry, Korea University, Korea
1Department of Chemistry, Seoul Women's University, Korea
Abstract We synthesized two isomeric N-heterocyclic (NHC) carbene Ir(III) complexes, f-Ir-(dbfmi)3 (1) and m-Ir-(dbfmi)3 (2), and the photophysical and electrochemical properties of the compounds were investigated. Both isomers showed efficient emission in dichloromethan solution with quantum yield 53% and 68%, respectively, arised from the unusual properties of the N-heterocyclic carbene (NHC) ligand–that is, the complexes possess a strong metal–ligand bond that destabilizes the non-radiative metal–centered ligand-field states. Depending on their configurations, they showed different photophysical properties which reveal that the emission of facial isomer is relatively dominance of 3LC state while meridional isomer shows significant 3MLCT character. Furthermore, emission lifetime of both isomers were gradually increase in rigid environment which indicates their efficiencies can be improved when they utilized in OLEDs. Accordingly, both isomeric complexes were used as dopant material for blue PHOLED device. Both devices showed high efficiencies with EQE of up to 18% and low turn-on voltage (≈ 2.8 V). Most importantly, device with m-Ir-(dbfmi)3 showed deep blue CIE chromaticity diagrams with (0.14, 0.11).
E-mail wogus0618@korea.ac.kr