High-performance polymer-based electrophosphorescent light-emitting diodes
High-performance polymer-based electrophosphorescent light-emitting diodes
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DOI：
10.1002/polb.10645
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发表时间：
2003-11-01
影响因子：
--
通讯作者：
Heeger, AJ
中科院分区：
文献类型：
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作者：
Gong, X;Ostrowski, JC;Heeger, AJ
以三-[9,9-二己基-2-（吡啶基-2‘）)芴铱（III） [Ir(DPF)(3)]、三-{9,9-二己基-2-[苯基-4’-(-吡啶基-2'-)]芴}铱（III） [Ir(DPPF)(3)]和三-[2,5-双-2'-（9,9'-二己基芴）铱][Ir(HFP)(3)]为客体，与聚乙烯基咔唑（PVK）与2-叔丁基苯基-5-联苯-1,3,4-恶二氮基（PBD）、聚（9,9-二辛基芴基-2,7-二基）（PFO）共混，制备了高性能的电磷光发光二极管（led）。和聚（9,9-二己基芴）-co-2,5-二氰苯（PF3CNP1）作为宿主。用PVK-PBD制成的器件表现出最高的外量子效率（qext）、发光效率（LE）和亮度(L)。例如，当QE(ext) = 10% ph/el, LE = 36 cd/A, L > 8300 cd/m(2)时，掺杂Ir（DPPF）的PVK-PBD(3)发射出黄绿色；当QE(ext) = 5% ph/el, LE = 7.2 cd/A, L > 2700 cd/m(2)时，掺杂Ir（DPPF）的PVK-PBD(3)发射出红色。以共轭聚合物PFO为主体，Ir(HFP)(3)为客体，获得了低导通电压（5 V）， QE(ext)= 4.5% ph/el, LE = 6.2 cd/ a, L > 1000 cd/m(2)的红色电磷光led。用掺杂Ir(HFP)(3)的共轭共聚物PF3CNP1制备的电磷光led的QE(ext) = 1.5% ph/el, LE = 3 cd/A, L = 2200 cd/m(2)。这些器件在室温直流驱动下表现出良好的工作稳定性。福斯特能量转移在实现这些电磷光器件的高效率方面起着次要作用；直接序贯电荷捕获似乎是主要的操作机制。这些结果表明，通过直接从溶液中加工活性材料制备聚合物基led可以获得高性能的电磷光。(C) 2003 Wiley期刊有限公司[J] .高分子材料科学与工程学报，2003,19 (4):391 - 391
High-performance electrophosphorescent light-emitting diodes (LEDs) were demonstrated with tris-[9,9-dihexyl-2-(pyridinyl-2') fluorenel iridium(III) [Ir(DPF)(3)], tris-{9,9-dihexyl-2-[phenyl-4'-(-pyridin-2"-yl)] fluorene} iridium(III) [Ir(DPPF)(3)], and tris-[2,5-bis-2'-(9,9'-dihexylfluorene) iridium] [Ir(HFP)(3)] as guests and poly(vinylcarbazole) (PVK) blended with 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazoI (PBD), poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO), and poly(9,9-dihexylfluorene)-co-2,5-dicyanophenylene (PF3CNP1) as hosts. The devices made with PVK-PBD exhibited the highest external quantum efficiency QEext), luminous efficiency (LE) and luminance (L). For example, yellowish green emission from PVK-PBD doped with Ir(DPF)(3) was observed with QE(ext) = 10% ph/el, LE = 36 cd/A, and L > 8300 cd/m(2), and red emission from PVK-PBD doped with Ir(DPPF)(3) was observed with QE(ext) = 5% ph/el, LE = 7.2 cd/A, and L > 2700 cd/m(2). Red electrophosphorescent LEDs with a low turn-on voltage (5 V), QE(ext)= 4.5% ph/el, LE = 6.2 cd/A, and L > 1000 cd/m(2) were achieved with the conjugated polymer, PFO, as the host and Ir(HFP)(3) as the guest. Electrophosphorescent LEDs fabricated with the conjugated copolymer PF3CNP1 doped with Ir(HFP)(3) exhibited QE(ext) = 1.5% ph/el and LE = 3 cd/A with L = 2200 cd/m(2). These devices exhibited good operational stability under DC drive at room temperature. Forster energy transfer played a minor role in achieving the high efficiencies in these electrophosphorescent devices; direct sequential charge trapping appeared to be the main operating mechanism. These results demonstrated that high-performance electrophosphorescence can be obtained from polymer-based LEDs that are fabricated by processing the active materials directly from solution. (C) 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2691-2705, 2003