Controlling the orientation of the emissive dipole has led to a renaissance of organic light-emitting diode (OLED) research, with external quantum efficiencies (EQEs) of >30% being reported for phosphorescent emitters. These highly efficient OLEDs are generally manufactured using evaporative methods and are comprised of small-molecule heteroleptic phosphorescent iridium(III) complexes blended with a host and additional layers to balance charge injection and transport. Large area OLEDs for lighting and display applications would benefit from low-cost solution processing, provided that high EQEs could be achieved. Here, we show that poly(dendrimer)s consisting of a non-conjugated polymer backbone with iridium(III) complexes forming the cores of first-generation dendrimer side chains can be co-deposited with a host by solution processing to give highly efficient devices. Simple bilayer devices comprising the emissive layer and an electron transport layer gave an EQE of >20% at luminances of up to ≈300 cd/m², showing that polymer engineering can enable alignment of the emissive dipole of solution-processed phosphorescent materials.

控制发射偶极子的方向导致了有机发光二极管（OLED）研究的复兴，据报道磷光发射体的外部量子效率（EQE）> 30％。这些高效的OLED通常使用蒸发方法制造，并且由与主体和其他层混合以平衡电荷注入和传输的小分子杂散性磷光铱（III）配合物组成。如果可以实现高EQE，则用于照明和显示应用的大面积OLED将受益于低成本的解决方案处理。这里，我们表明，由非共轭聚合物主链与形成第一代树枝状聚合物侧链核心的铱（III）配合物组成的聚（树枝状聚合物）可以通过溶液加工与宿主共沉积，从而提供高效的器件。由发光层和电子传输层组成的简单双层器件在高达≈300cd / m的亮度下给出的EQE大于20％^{如图2所示}，表明聚合物工程可以使溶液处理的磷光材料的发射偶极排列。