Syntheses and electroluminescence properties of conjugated poly(p-phenylene vinylene) derivatives bearing dendritic pendants
writer：tang rp, et al
keywords：electroluminescence
source：期刊
specific source：Journal of Polymer Science Part A: Polymer Chemistry
Issue time：2005年
A series of new poly(p-phenylene vinylene) derivatives with different dendritic
pendants—poly{2-[30,50-bis(2@-ethylhexyloxy)benzyloxy]-1,4-phenylenevinylene}
(BE–PPV), poly{2-[30,50-bis(3@,7@-dimethyl)octyloxy]-1,4-phenylenevinylene} (BD–PPV), poly(2-{30,50-bis[3@,5@-bis(2000-ethylhexyloxy)benzyloxy]benzyloxy}-1,4-phenylenevinylene) (BBE–PPV), poly(2-{30,50-bis[3@,5@-bis(3000,7000-dimethyloctyloxy)benzyloxy]benzyloxy}-1,4-phenylenevinylene) (BBD–PPV), and poly[(2-{30,50-bis[3@,5@-bis(2000-ethylhexyloxy)-benzyloxy]benzyloxy}-1,4-phenylenevinylene)-co-(2-{30,50-bis[3@,5@-bis(3000,7000-dimethyloctyloxy)
benzyloxy]benzyloxy}-1,4-phenylenevinylene)] (BBE-co-BBD–PPV; 1:1) were successfully synthesized according to the Gilch route. The structures and properties of the monomers and the resulting conjugated polymers were characterized with 1H and 13C NMR, elemental analysis, gel permeation chromatography, thermogravimetric analysis, ultraviolet–visible absorption spectroscopy, photoluminescence, and electroluminescence spectroscopy. The obtained polymers possessed excellent solubility in common solvents and good thermal stability, with a 5% weight loss temperature of more than 328 8C. The weight-average molecular weights and polydispersity indices of BE–PPV, BD–PPV, BBE–PPV, BBD–PPV, and BBE-co-BBD–PPV (1:1) were in the range of 1.33–2.28 105 and 1.35–1.53, respectively. Doublelayer light-emitting diodes (LEDs) with the configuration of indium tin oxide/polymer/tris(8-hydroxyquinoline) aluminum/Mg:Ag/Ag devices were fabricated, and they emitted green-yellow light. The turn-on voltages of BE–PPV, BD–PPV, BBE–PPV, BBD–PPV, and BBE-co-BBD–PPV (1:1) were approximately 5.6, 5.9, 5.5, 5.2, and4.8 V, respectively. The LED devices of BE–PPV and BD–PPV possessed the highest electroluminescent performance; they exhibited maximum luminance with about 860 cd/m2 at 12.8 V and 651 cd/m2 at 13 V, respectively. The maximum luminescence efficiency of BE–PPV and BD–PPV was in the range of 0.37–0.40 cd/A.