Highly efficient light-emitting electrochemical cells (LECs) have attracted tremendous interest because of their simple structures and low-cost fabrication processing, showing great potential for full-color displays and solid-state lighting. In this work, we rationally designed and synthesized two red-emitting cationic Ir(III) complexes, [Ir(tBuPBI)2(biq)]PF6 (R1) and [Ir(tBuPBI)2(qibi)]PF6 (R2), in which a tert-butyl-functionalized 1,2-diphenyl-1H-benzo[d]imidazole (PBI) unit and conjugated 2,2'-biquinoline (biq) and 2-(1-phenyl-1H-benzo[d]imidazol-2-yl)quinolone (qibi) were employed as cyclometalated and ancillary ligands, respectively. The introduced tert-butyl group led to homogeneous and highly emissive thin films by increasing the solubility and suppressing the strong intermolecular interactions due to steric hindrance. Based on the abovementioned high-quality emissive layer, high-efficiency LECs were achieved. An efficient red-emitting LEC fabricated on a glass substrate achieved a current efficiency (ηC) of 7.18 cd/A and an external quantum efficiency (ηext) of 9.32%. By doping both complexes into a blue-green-emitting cationic Ir(III) complex, high-performance white LECs were also successfully fabricated with Commission International de L'Eclairage (CIE) coordinates of (0.39,0.39), a ηC of 17.43 cd/A, and a ηext of 8.92%. In addition, we also fabricated flexible red and white LECs with outstanding efficiencies and mechanical flexibilities. The ηC and ηext values of a flexible white LEC could be as high as 13.50 cd/A and 6.86%, respectively. The efficiency of the flexible device remained at approximately 95% of the initial value after 500 bends with a radius of curvature of 5 mm, demonstrating the great potential of these complexes for full-color displays and flexible optoelectronics.

中文翻译：

---

高效，柔性，单色和白色发光电化学电池的高效有机金属Ir（III）配合物的合理设计。

高效发光电化学电池（LEC）由于其简单的结构和低成本的制造工艺而引起了极大的兴趣，显示出全彩显示器和固态照明的巨大潜力。在这项工作中，我们合理地设计和合成了两种红色发射阳离子Ir（III）配合物[Ir（tBuPBI）2（biq）] PF6（R1）和[Ir（tBuPBI）2（qibi）] PF6（R2），其中叔丁基官能化的1,2-二苯基-1H-苯并[d]咪唑（PBI）单元和共轭2,2'-联喹啉（biq）和2-（1-苯基-1H-苯并[d]咪唑-2-基）喹诺酮（qibi）分别用作环金属化和辅助配体。引入的叔丁基通过增加溶解度并抑制由于位阻引起的强烈的分子间相互作用，形成了均匀且高发射率的薄膜。基于上述高质量发射层，实现了高效LEC。在玻璃基板上制造的高效红色发光LEC的电流效率（ηC）为7.18 cd / A，外部量子效率（ηext）为9.32％。通过将两种配合物掺入发出蓝绿色光的阳离子Ir（III）配合物中，还成功制备了具有国际照光委员会（CIE）坐标（0.39,0.39），ηC为17.43 cd的高性能白色LEC。 / A，ηext为8.92％。此外，我们还制造了具有出色效率和机械柔韧性的柔性红色和白色LEC。柔性白色LEC的ηC和ηext值分别高达13.50 cd / A和6.86％。