| 초록 |
Three materials of electron transport type host, 1DBF-2CNCZ, 2DBF-2CNCZ and 4DBF-2CNCZ were synthesized and indicated for blue thermally activated delayed fluorescent (TADF) organic light-emitting diodes (OLEDs). The three host materials were commonly introduced with a benzonitirle, a dicyanocarbazole, and a dibenzofuran units as the electron transport moieties, and had an isomeric molecular structure with different substitution positions of the dibenzofuran moiety. They showed high triplet energy above 3.0 eV by a twisted molecular structure and were applied to the mixed host system as the electron transport type hosts with a hole transport type mCBP host for blue TADF OLEDs. The blue TADF OLEDs fabricated with the 1DBF-2CNCZ host achieved high EQE over 20% and 31 h lifetime up to 75% of initial luminance at 500 cd/m2 at a mixed host composition of mCBP:1DBF-2CNCZ (25:75). |
