PMSE 8 |
| New electroluminescent polymers (poly(9,9'-dioctylfluorene(FL)-co- oligo-para-phenylene-(E)-vinylenes(OPV)-co-benzo[2,3,5]thiadiazole(BT)) possess hole-transporting or electron-transporting units or both in the main chains. Six different copolymers (P50 to P0) with electron-rich OPV and electron-deficient BT moieties were incorporated in the polymer backbone to improve the electron-transporting and hole-transporting characteristics, respectively. Owing to the incorporation of the OPV and BT units, PLED devices based on the copolymer at FL/OPV/BT molar ratio of 50%/48%/2% exhibit greater brightness and efficiency (up to 799 cd/m2 and 1.42 cd/A) than those devices based on the other composition polymers. White light emitting devices were also fabricated using conjugated polymer blends. The copolymer of P0 (FL/OPV/BT=50%/50%/0) and MEH-PPV were employed for the polymer blends. The white light emission polyblends can be adjusted by the blend ratios of P0 to MEH-PPV. The electroluminescent of the polyblends with P0/MEH-PPV=99/1 exhibits the Commission Internationale (CIE) 1931 coordinates of (0.32, 0.33), with the maximum luminance of 1228cd /m2 and current efficiency of 1.71 cd /A. The energy transfer was found as host-guest mechanism in polyfluorene(PF)/poly(FL-BT-OPV), based on the PF/ poly(FL-BT-OPV) weight ratio of polyblends. The PLED device shows the 4240 cd /m2 luminance and 2.33 cd/A high current efficiency. |
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New Concepts in Polymeric Materials
8:00 AM-11:20 AM, Sunday, August 19, 2007 Westin Boston Waterfront -- Grand Ballroom D, Oral
Division of Polymeric Materials: Science & Engineering |