Synthesis of New Fluorene-Based Copolymers Containing an Anthracene Derivative and Their Applications in Polymeric Light-Emitting Diodes
作者:Kyoungmi Lee、Jong-Hwa Park、Moo-Jin Park、Jonghee Lee、Hong-Ku Shim
DOI:10.1166/jnn.2011.3709
日期:2011.5.1
We report the synthesis of copolymers containing fluorene and highly soluble anthracene derivatives, of general formula, poly9,9′-bis-(4-octoloxy-phenyl)-fluorene-2,7-diyl-co-9,10-bis-(decy-1-ynyl)-anthracene-2,6-diyl}s (PFAnts). The PFAnts were synthesized via Suzuki coupling and the feed ratios of the anthracene derivative (Ant) were 1, 5, 10, 30, and 50 mol % of the total amount of monomer. PFAnts showed well-defined high molecular weights and were more soluble in conventional organic solvents. The photoluminescence spectra of PFAnts shifted to longer wavelengths with increases in Ant proportion and the PFAnts emitted various colors varying from greenish-blue to orange. The highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels trended toward enhanced hole and electron recombination balance as the Ant proportion increased, due to the better electron-accepting ability of the anthracene moiety compared to the fluorene moiety. Polymeric light-emitting diodes with the configurations ITO/PEDOT:PSS(40 nm)/polymer(60 nm)/Ca(10 nm)/Al(100 nm) (Device A) and ITO/PEDOT:PSS(40 nm)/polymer(60 nm)/Balq(40 nm)/LiF(1 nm)/Al(100 nm) (Device B) were fabricated using the polymers as emissive layers. Especially, Device B with PFAnt01 exhibited the highest measured maximum brightness of 1760 cd/m2 at 14 V, a maximum current efficiency of 1.66 cd/A, and a maximum external quantum efficiency of 0.70%.
我们报道了包含氟烯和高溶解性蒽衍生物的共聚物的合成,通式为聚9,9′-双-(4-辛氧基苯)-氟烯-2,7-二基-co-9,10-双-(癸-1-炔基)-蒽-2,6-二基}s(PFAnts)。PFAnts 通过铃木偶联法合成,蒽衍生物(Ant)的投料比例分别为总单体量的 1%、5%、10%、30% 和 50%。PFAnts 显示出明确的高分子量,并在常规有机溶剂中更具溶解性。PFAnts 的光致发光光谱随着 Ant 比例的增加而向长波长方向移动,发出从青蓝色到橙色的多种颜色。由于与氟烯基相比,蒽基具有更好的电子接受能力,最高占据分子轨道和最低未占据分子轨道的能级随着 Ant 比例的增加而趋向于增强孔和电子复合平衡。使用这些聚合物作为发光层,制备了配置为 ITO/PEDOT:PSS(40 nm)/聚合物(60 nm)/Ca(10 nm)/Al(100 nm)(装置 A)和 ITO/PEDOT:PSS(40 nm)/聚合物(60 nm)/Balq(40 nm)/LiF(1 nm)/Al(100 nm)(装置 B)的聚合物发光二极管。特别是,装置 B 中的 PFAnt01 在 14 V 时测得最高亮度为 1760 cd/m²,最大电流效率为 1.66 cd/A,以及最大外量子效率为 0.70%。