| 초록 |
Efficient blue electrophosphorescence was achieved from iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,C2]picolinate (FIrpic) covalently bonded to the carbazole-based polymer host (poly(9-dodecyl-3-vinylcarbazole); CP0). The molar content of FIrpic-containing monomer units were 0.8 ~ 10.6%: CP1 (0.8%), CP2 (2.9%), CP3 (5.3%), and CP4 (10.6%). Phase segregation in the CPn copolymer was significantly suppressed compared to that in the doped analogues, which was observed by CLSM and TEM. The photoluminescence spectra of the carbazole-based polymer host (CP0) overlapped with the absorption band of FIrpic and the T1 level of CP0 (-2.6 eV) was higher than that of FIrpic (-3.1 eV) ensuring highly efficient exothermic energy transfer (triplet-triplet transfer as well as Forster transfer). Electroluminescence (EL) devices employing CPn polymers as emitting layer showed exclusive FIrpic emission due to the efficient energy transfer and subsequent exciton confinement within the FIpic. |
