Iridium(III) complexes adopting 1,2-diphenyl-1H-benzoimidazole ligands for highly efficient organic light-emitting diodes with low efficiency roll-off and non-doped feature
Iridium(III) complexes adopting 1,2-diphenyl-1H-benzoimidazole ligands for highly efficient organic light-emitting diodes with low efficiency roll-off and non-doped feature
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采用1,2-二苯基-1H-苯并咪唑配体的铱(III)配合物用于具有低效率滚降和非掺杂特性的高效有机发光二极管
DOI：
10.1039/c3tc32092h
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发表时间：
2014-01-01
影响因子：
6.4
通讯作者：
Zhu, Dongxia
中科院分区：
文献类型：
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作者：
Cao, Hongtao;Sun, Haizhu;Zhu, Dongxia
成功合成并表征了两种采用1,2-二苯基-1H-苯并咪唑（Hpbi）作为环金属配体的新型铱（III）配合物（pbi）2Ir（mtpy）（1）和（pbi）2Ir（pbim）（2）。 1 和 2 在 298 K 的 CH2Cl2 中分别获得了 501 和 536 nm 处的强发射以及 48% 和 91% 的高光致发光量子产率。量子化学计算和光物理性质表明，主要的3MLCT（金属到配体电荷转移）状态与3LLCT（配体到配体电荷转移）和3LC（配体中心3π–π*）特征混合有助于其磷光发射。基于 1 和 2 的掺杂有机发光二极管 (OLED) 显示出 45.0 cd A−1 的峰值电流效率和 47.9 lm W−1 的功率效率，同时效率滚降值非常低。在他们的非掺杂 OLED 中，还实现了 24.4 cd A−1 和 26.3 lm W−1 的高效率。这些引人注目的结果表明，配合物 1 和 2 为未来高性能 OLED 的开发开辟了有趣的前景。
Two novel iridium(III) complexes (pbi)2Ir(mtpy) (1) and (pbi)2Ir(pbim) (2) adopting 1,2-diphenyl-1H-benzoimidazole (Hpbi) as cyclometalated ligands were successfully synthesized and characterized. Strong emissions at 501 and 536 nm with high photoluminescence quantum yields of 48% and 91% in CH2Cl2 at 298 K were obtained for 1 and 2, respectively. The quantum chemical calculations and the photophysical properties indicated that the dominant 3MLCT (metal-to-ligand charge-transfer) state mixed with 3LLCT (ligand-to-ligand charge-transfer) and 3LC (ligand-centered 3π–π*) characters contributed to their phosphorescence emissions. Doped organic light-emitting diodes (OLEDs) based on 1 and 2 showed a peak current efficiency of 45.0 cd A−1 and power efficiency of 47.9 lm W−1 accompanied by very low efficiency roll-off values. In their non-doped OLEDs, high efficiencies of 24.4 cd A−1 and 26.3 lm W−1 were achieved as well. These appealing results reveal that complexes 1 and 2 open interesting perspectives for the development of high-performance OLEDs in the future.