State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
Sci Rep. 2016 Dec 8;6:38478. doi: 10.1038/srep38478.
Due to the high quantum efficiency and wide scope of emission colors, iridium (Ir) (III) complexes have been widely applied as guest materials for OLEDs (organic light-emitting diodes). Contrary to well-developed Ir(III)-based red and green phosphorescent complexes, the efficient blue emitters are rare reported. Like the development of the LED, the absence of efficient and stable blue materials hinders the widely practical application of the OLEDs. Inspired by this, we designed two novel ancillary ligands of phenyl(pyridin-2-yl)phosphinate (ppp) and dipyridinylphosphinate (dpp) for efficient blue phosphorescent iridium complexes (dfppy)Ir(ppp) and (dfppy)Ir(dpp) (dfppy = 2-(2,4-difluorophenyl)pyridine) with good electron transport property. The devices using the new iridium phosphors display excellent electroluminescence (EL) performances with a peak current efficiency of 58.78 cd/A, a maximum external quantum efficiency of 28.3%, a peak power efficiency of 52.74 lm/W and negligible efficiency roll-off ratios. The results demonstrated that iridium complexes with pyridinylphosphinate ligands are potential blue phosphorescent materials for OLEDs.
由于铱（Ir）（III）配合物具有高光量子效率和宽发射颜色范围，因此已被广泛应用于有机发光二极管（OLED）的客体材料。与开发成熟的基于 Ir(III)的红色和绿色磷光配合物相反，高效的蓝色发射体很少有报道。与 LED 的发展类似，缺乏高效和稳定的蓝色材料阻碍了 OLED 的广泛实际应用。受此启发，我们设计了两种新型辅助配体苯并（吡啶-2-基）膦酸酯（ppp）和二吡啶基膦酸酯（dpp），用于高效蓝色磷光铱配合物（dfppy）Ir（ppp）和（dfppy）Ir（dpp）（dfppy = 2-（2,4-二氟苯基）吡啶），具有良好的电子传输性能。使用新型铱磷光体的器件显示出优异的电致发光（EL）性能，峰值电流效率为 58.78 cd/A，最大外量子效率为 28.3%，峰值功率效率为 52.74 lm/W，效率滚降比可忽略不计。结果表明，具有吡啶基膦酸酯配体的铱配合物是用于 OLED 的潜在蓝色磷光材料。
