| 초록 |
In this study, highly efficient thermally activated delayed fluorescent (TADF) emitters, 9,9′,9″-(5-(4,6-diphenyl-1,3,5-triazin-2-yl)benzene-1,2,3-triyl)tris(9H-carbazole) (TCzTrz), 9,9′,9″-(5-(4,6-diphenyl-1,3,5-triazin-2-yl)benzene-1,2,3-triyl)tris(3,6-dimethyl-9H-carbazole) (TmCzTrz) and 9,9'-(2-(3,6-dimethyl-9H-carbazol-9-yl)-5-(4,6-diphenyl-1,3,5-triazin-2-yl)-1,3-phenylene)bis(9H-carbazole) (DCzmCzTrz), which contain three carbazole type donors in their backbone structure. Three compounds showed small singlet-triplet gaps of 0.07~0.20 eV and high photoluminescence quantum yields of 84~100%. As a result, blue device with TCzTrz as a TADF emitter achieved high external quantum yield (EQE) of 25.0% and green devices with TmCzTrz and DCzmCzTrz also showed high EQE of 25.5 and 21.3%, respectively. |
