Synthesis, photoluminescence and electroluminescence properties of iridium complexes with bulky carbazole dendrons
Synthesis, photoluminescence and electroluminescence properties of iridium complexes with bulky carbazole dendrons
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DOI：
10.1016/j.orgel.2009.01.014
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发表时间：
2009-05
影响因子：
3.2
通讯作者：
N. Iguchi;Yong‐Jin Pu;K. Nakayama;M. Yokoyama;J. Kido
中科院分区：
文献类型：
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作者：
N. Iguchi;Yong‐Jin Pu;K. Nakayama;M. Yokoyama;J. Kido
我们合成了具有大咔唑树枝的可溶液加工的铱配合物，fac-tris[2-{3-(3,5-双(3,6-二正丁基咔唑-9-基)苯基)苯基)吡啶]铱(III)(mCP)3Ir和 fac-双[2-{3-(3,5-双(3,6-二正丁基咔唑-9-基)苯基)苯基}吡啶][2-{3-(3,5-二(4-吡啶基)苯基)苯基}吡啶]铱(III)(mCP)2(bpp)Ir。 (mCP)3Ir和(mCP)2(bpp)Ir在其稀释溶液中的光致发光量子效率(PLQE)分别为91%和84%。即使在纯薄膜中，(mCP)3Ir 的 PLQE 也高达 49%，(mCP)2(bpp)Ir 的 PLQE 也高达 29%。树枝状配体（2.8eV）2-[3-{3,5-双（3,6-二正丁基咔唑-9-基）苯基}]吡啶10和树枝状分子（2.9eV）3,5-双（3,6-二正丁基咔唑-9-基）苯7的三重态激子能级足够高于核心配合物的三重态激子能级 Ir(ppy)3(2.6eV)。 (mCP)2(bpp)Ir单层发光器件的外量子效率(EQE)远高于(mCP)3Ir，因为(mCP)2(bpp)Ir与阴极金属有更好的亲和力。当使用电子传输和空穴阻挡材料时，双层器件的EQE在100cd/m2下显着提高至(mCP)3Ir的8.3%和(mCP)2(bpp)Ir的5.4%。
We synthesized solution-processable iridium complexes having bulky carbazole dendrons, fac-tris[2-{3-(3,5-bis(3,6-di-n-butylcarbazol-9-yl)phenyl)Phenyl)pyridine]iridium (III) (mCP)3Ir and fac-bis[2-{3-(3,5-bis(3,6-di-n-butylcarbazol-9-yl)phenyl)phenyl}pyridine][2-{3-(3,5-di(4-pyridyl)phenyl)phenyl}pyridine]iridium (III) (mCP)2(bpp)Ir. Photoluminescence quantum efficiencies (PLQEs) of (mCP)3Ir and (mCP)2(bpp)Ir in their diluted solutions were 91% and 84%, respectively. They showed high PLQEs of 49% for (mCP)3Ir and 29% for (mCP)2(bpp)Ir even in a neat film. The triplet exciton energy level of the dendronized ligand (2.8eV), 2-[3-{3,5-bis(3,6-di-n-butylcarbazol-9-yl)phenyl}]pyridine 10, and the dendron (2.9eV), 3,5-bis(3,6-di-n-butylcarbazol-9-yl)benzene 7, are enough higher than that of the core complex Ir(ppy)3(2.6eV). External quantum efficiency (EQE) of single layer light-emitting device with (mCP)2(bpp)Ir was much higher than that of (mCP)3Ir because of better affinity of (mCP)2(bpp)Ir to cathode metal. When an electron transporting and hole-blocking material was used, the EQEs of double layer devices were dramatically improved to 8.3% for (mCP)3Ir and 5.4% for (mCP)2(bpp)Ir at 100cd/m2.