<em>N</em>-Heterocyclic Carbene based Tetradentate Pt(II) Complexes for Blue Phosphorescent Organic Light-Emitting Diodes
발표자
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초록
내용
Two novel classes of N-heterocyclic carbene (NHC) based tetradentate Pt(II) complexes possessing bulky benzyl groups and pyridoimidazole ligands were designed and synthesized to produce efficient blue phosphorescent organic light-emitting diodes (PHOLEDs). Notably, pyridoimidazole and bulky benzyl groups efficiently reduced steric hindrance, vibrational peaks, and intermolecular interactions. The complexes exhibited blue electroluminescence (EL) emission at 466 nm with a small full-width half maximum (FWHM) of 26 nm and completely suppressed vibrational emission peaks. Blue PHOLEDs, at 5 wt% Pt(t-BuBnOCzPy) and Pt(BnOCz4t-BuPy) doping ratios exhibited maximum external quantum efficiencies (EQEmax) of 19 and 18.6%, maximum power efficiencies (PEmax) of 25.5 and 24.9 cd m-2, and maximum current efficiencies (CEmax) of 24.3 and 24.3 cd m-2 with Commission International de I'Eclairage (CIEx,y) color coordinates of (0.13, 0.17) and (0.13, 0.17), respectively.