Abstract
Highly-efficient blue phosphorescent light-emitting diodes were fabricated based on a conjugated-polymer host by doping bis(2-(4,6-difluorophenyl)-pyridinato-N,C2′) picolinate (FIrpic) into poly(9,9-dioctylfluorene) (PFO). Previously, conjugated polymers were not considered as potential hosts for blue phosphorescent dyes because of their low-lying triplet energy levels. Energy back transfer would occur and lead to poor luminescent efficiency in both photoluminescence (PL) and electroluminescence (EL) processes. However, by inserting a hole-transporting layer of poly(N-vinylcarbazole) (PVK), the energy back transfer was suppressed. At low FIrpic-doping concentrations, PFO emissions were completely quenched; with 8 wt% FIrpic, a maximum luminous efficiency of 11.5 cd/A was achieved.
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Niu, Q., Zhang, Y., Wang, Y. et al. High-efficiency conjugated-polymer-hosted blue phosphorescent light-emitting diodes. Chin. Sci. Bull. 57, 3639–3643 (2012). https://doi.org/10.1007/s11434-012-5247-3
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DOI: https://doi.org/10.1007/s11434-012-5247-3