| 초록 |
Three ortho-, meta- and para- substituted thermally activated delayed fluorescent (TADF) emitting materials, 5-(2-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-5H-benzofuro[3,2-c]carbazole (oBFCzTrz), 5-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-5H-benzofuro[3,2-c]carbazole (mBFCzTrz) and 5-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-5H-benzofuro[3,2-c]carbazole (pBFCzTrz), were synthesized to investigate the effect of linked position between electron donor and acceptor moieties. oBFCzTrz showed small singlet-triplet energy gap of 0.002 eV, high photoluminescence quantum yield of 97.9% and short excited state lifetime of 5.4 μs. As a result, blue TADF device using oBFCzTrz showed high quantum efficiency above 20%, little efficiency reduction at high luminance and long device lifetime. |
