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A novel bipolar polymer host PC10CzPO, carrying hole-transporting carbazole and electron-transporting triphenylphosphine oxide units in the oxygen-interrupted main chain, was synthesized and characterized. In addition to its excellent thermal stability and miscibility with phosphors, PC10CzPO is also reported to have a triplet energy (ET) as high as 2.83 eV due to oxygen-interrupted π-conjugation, ensuring that PC10CzPO can be used as a suitable host material. The PC10CzPO-based phosphorescent devices were investigated and compared, while doping with typical blue phosphor {iridium(III)[bis(4,6-difluorophenyl)pyridinato-N, C2]picolinate, FIrpic)}, green phosphor {tris[2-(p-tolyl)pyridine]iridium(III), Ir(mppy)3}, and red phosphor [bis(1-phenyl-isoquinoline-C2,N)(acetylacetonato)iridium(III), Ir(piq)2acac]. As a result, the FIrpic-based blue devices showed better device performances than those of red and green devices, which was ascribed to more effective energy transfer. This indicates that the choice of proper host and dopant emitters to fabricate phosphorescent polymer light emitting diodes (PhPLED) is a simple and effective approach to optimize device performances. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44461.

A novel fluorene-alt-carbazole polymer host Poly(9,9-dioctyl-9H-fluorene-2,7-diyl-alt-N-tetrahydropyran-3,6-carbazole) (PFCz), composed of N-tetrahydropyran-3,6-carbazole and 9,9-dioctyl-2,7-fluorene in the polymer backbone, was synthesized by Suzuki coupling. The PFCz possesses good thermal stability and proper lowest unoccupied molecular orbital (LUMO)/highest occupied molecular orbital (HOMO) energy levels to facilitate the injection and transport of electrons and holes. Upon doping with blue, green, and red phosphors, red - green - blue (R-G-B) phosphorescent devices hosted by PFCz have been fabricated and investigated. In contrast to those of blue and green devices, the red devices give better performances with a maximum luminous efficiency of 4.88 cd/A and a maximum power efficiency of 1.85% at 149.84 cd/m2, due to favorable triplet energy level (ET) of PFCz for red phosphor, bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetonate)iridium(III) [Ir(MDQ)2(acac)]. Additionally, with different doped concentrations of Ir(MDQ)2(acac), the PFCz-related red devices emit nearly pure red light with Commission Internationale de L'Eclairage (CIE) coordinates of (0.57, 0.38), (0.60, 0.38), (0.61, 0.38), and (0.62, 0.38), which were very close to the standard red (0.66, 0.34) by the National Television System Committee. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 43234.