| 초록 |
Para and meta linked isomeric bistriazine units were developed as electron accepting moieties for thermally activated delayed fluorescent (TADF) emitting materials. Two TADF emitting materials using bistriazine, 9,9'-(2,5-bis(4,6-diphenyl-1,3,5-triazin-2-yl)-1,4-phenylene)bis(9H-carbazole) (p2Cz2Trz) and 9,9'-(4,6-bis(4,6-diphenyl-1,3,5-triazin-2-yl)-1,3-phenylene)bis(9H-carbazole) (m2Cz2Trz), were synthesized to study properties of bistriazine units. As a result, both materials showed TADF, and the m2Cz2Trz exhibited higher photoluminescence quantum yield (95.6%), smaller singlet and triplet energy gap (0.09 eV) and shorter delayed fluorescence lifetime (12.2 μs). TADF devices using the p2Cz2Trz and m2Cz2Trz showed high external quantum efficiencies of 12.5 and 18.5% with color coordinates of (0.39, 0.58) and (0.20, 0.47), respectively. |
