Organic light‐emitting diodes (OLEDs) are one of the most promising technologies for future displays and lighting. Compared with the blue and green OLEDs that have achieved very high efficiencies by using phosphorescent Ir(III) complexes, the red OLEDs still show relatively low efficiencies because of the lack of high‐performance red‐emitting Ir(III) complexes. Here, three highly efficient asymmetric red‐emitting Ir(III) complexes with two different cyclometalating ligands made by incorporating only one electron‐deficient triarylboron group into the nitrogen heterocyclic ring are reported. These complexes show enhanced photoluminescence quantum yields up to 0.96 and improved electron transporting capacity. In addition, the asymmetric structure can help to improve the solubility of Ir(III) complexes, which is crucial for fabricating OLEDs using the solution method. The photoluminescent and oxidation–reduction properties of these Ir(III) complexes are investigated both experimentally and theoretically. Most importantly, a solution‐processed red OLED achieves extremely high external quantum efficiency, current efficiency, and power efficiency with values of 28.5%, 54.4 cd A⁻¹, and 50.1 lm W⁻¹, respectively, with very low efficiency roll‐off. Additionally, the related device has a significantly extended operating lifetime compared with the reference device. These results demonstrate that the asymmetric diarylboron‐based Ir(III) complexes have great potential for fabricating high‐performance red OLEDs.

中文翻译：

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外部量子效率高于28％的固溶处理磷光有机发光二极管的基于二芳基硼的不对称红色Ir（III）配合物

有机发光二极管（OLED）是未来显示器和照明领域最有前途的技术之一。与通过使用磷光Ir（III）配合物实现非常高效率的蓝色和绿色OLED相比，由于缺少高性能的红色发光Ir（III）配合物，红色OLED仍然显示出相对较低的效率。在此，报道了三种高效不对称发红光的Ir（III）配合物，具有两个不同的环金属化配体，这些配合物是通过仅将一个缺电子的三芳基硼基团掺入氮杂环而制得的。这些配合物显示出高达0.96的增强的光致发光量子产率和改善的电子传输能力。此外，不对称结构有助于提高Ir（III）配合物的溶解度，这对于使用溶液法制造OLED至关重要。通过实验和理论研究了这些Ir（III）配合物的光致发光和氧化还原性质。最重要的是，经过溶液处理的红色OLED实现了极高的外部量子效率，电流效率和功率效率，其值为28.5％，54.4 cd A^-1和50.1 lm W ^-1，并且滚降效率非常低。另外，与参考设备相比，相关设备具有显着延长的工作寿命。这些结果表明，基于不对称二芳基硼的Ir（III）配合物在制备高性能红色OLED方面具有巨大潜力。