title: From Mononuclear to Dinuclear Iridium(III) Complex: Effective Tuning of the Optoelectronic Characteristics for Organic Light-Emitting Diodes.
abstract: Phosphorescent dinuclear iridium(III) complexes that can show high luminescent efficiencies and good electroluminescent abilities are very rare. In this paper, highly phosphorescent 2-phenylpyrimidine-based dinuclear iridium(III) complexes have been synthesized and fully characterized. Significant differences of the photophysical and electrochemical properties between the mono- and dinuclear complexes are observed. The theoretical calculation results show that the dinuclear complexes adopt a unique molecular orbital spatial distribution pattern, which plays the key role of determining their photophysical and electrochemical properties. More importantly, the solution-processed organic light-emitting diode (OLED) based on the new dinuclear iridium(III) complex achieves a peak external quantum efficiency (η(ext)) of 14.4%, which is the highest η(ext) for OLEDs using dinuclear iridium(III) complexes as emitters. Besides, the efficiencies of the OLED based on the dinuclear iridium(III) complex are much higher that those of the OLED based on the corresponding mononuclear iridium(III) complex.
authors.affiliation: MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behavior of Materials, and Institute of Chemistry for New Energy Materials, Department of Chemistry, School of Science, Xi'an Jiaotong University , Xi'an 710049, P. R. China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Yang
authors.affiliation: MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behavior of Materials, and Institute of Chemistry for New Energy Materials, Department of Chemistry, School of Science, Xi'an Jiaotong University , Xi'an 710049, P. R. China.
authors.forename: Xianbin
authors.initials: X
authors.lastname: Xu
authors.affiliation: MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behavior of Materials, and Institute of Chemistry for New Energy Materials, Department of Chemistry, School of Science, Xi'an Jiaotong University , Xi'an 710049, P. R. China.
authors.forename: Jing-shuang
authors.initials: JS
authors.lastname: Dang
authors.affiliation: MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behavior of Materials, and Institute of Chemistry for New Energy Materials, Department of Chemistry, School of Science, Xi'an Jiaotong University , Xi'an 710049, P. R. China.
authors.forename: Guijiang
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Institute of Molecular Functional Materials, Department of Chemistry, and Institute of Advanced Materials, Hong Kong Baptist University , Waterloo Road, Kowloon Tong, Hong Kong, P. R. China.|HKBU Institute of Research and Continuing Education, Shenzhen Virtual University Park , Shenzhen 518057, P. R. China.
authors.forename: Cheuk-Lam
authors.initials: CL
authors.lastname: Ho
authors.affiliation: Institute of Molecular Functional Materials, Department of Chemistry, and Institute of Advanced Materials, Hong Kong Baptist University , Waterloo Road, Kowloon Tong, Hong Kong, P. R. China.|HKBU Institute of Research and Continuing Education, Shenzhen Virtual University Park , Shenzhen 518057, P. R. China.
authors.forename: Wai-Yeung
authors.initials: WY
authors.lastname: Wong