Three green-emitting heteroleptic iridium complexes with 2-(4,5,6-trifluorophenyl)pyridine, 2-(3,4,6-trifluorophenyl)pyridine, and 2-(3,4,5-trifluorophenyl)pyridine as main ligands and tetraphenylimidodiphosphinate (tpip) as the ancillary ligand were synthesized and characterized. The positions of the three fluorine atoms on the phenyl ring affect the emission properties of the complexes, and the application of Htpip as the ancillary ligand improves the electron mobility of the complexes to make it comparable to that of the popular electron transport material tris(8-hydroxyquinolinato)aluminium (Alq3) under the same electric fields. The organic light-emitting diodes (OLEDs) based on the above phosphorescent emitters {indium tin oxide (ITO)/1,1-bis[4-(di-p-tolyl-amino)phenyl]cyclohexane (TAPC), 30 nm/Ir complex (x wt.-%)/N,N′-dicarbazolyl-3,5-benzene (mCP), 15 nm/1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (TPBi), 45 nm/LiF (1 nm)/Al (100 nm)} exhibited good performances. The device doped with bis[2-(3,4,6-trifluorophenyl)pyridine](tetraphenylimidodiphosphinato)iridium [Ir(F3,4,6ppy)2(tpip)] (8 wt.-%) showed superior performance with a peak current efficiency (ηc) of 66.36 cd A–1 and a peak external quantum efficiency (ηext, EQE) of 25.7 % at 5.8 V, a maximum power efficiency (ηp) of 48.20 lm W–1 at 4.4 V, and a maximum luminance (Lmax) of 47627 cd m–2 at 12.6 V. Notably, the electroluminescence (EL) efficiency roll-off effects at relatively high current density in all devices are very mild, which helps them to obtain high efficiency at brightness. The results suggest that the three complexes, [Ir(F3,4,6ppy)2(tpip)] especially, would have potential applications in OLEDs.

中文翻译：

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以氟化 2-苯基吡啶为主配体和四苯基亚氨基二亚膦酸酯为辅助配体的铱 (III) 配合物的合成、光致发光和电致发光

三种以2-(4,5,6-三氟苯基)吡啶、2-(3,4,6-三氟苯基)吡啶和2-(3,4,5-三氟苯基)吡啶为主要配体的绿色发光杂配铱配合物合成并表征了作为辅助配体的四苯基亚氨基二膦酸酯（tpip）。苯环上三个氟原子的位置影响配合物的发射特性，Htpip作为辅助配体的应用提高了配合物的电子迁移率，使其与流行的电子传输材料tris(8)相媲美。 -羟基喹啉）铝（Alq3）在相同的电场下。基于上述磷光发光体{氧化铟锡(ITO)/1,1-双[4-(二-对甲苯基-氨基)苯基]环己烷(TAPC)的有机发光二极管(OLED)，30nm/ Ir 络合物 (x wt.-%)/N,N'-dicarbazolyl-3, 5-苯 (mCP)，15 nm/1,3,5-三(1-苯基-1H-苯并[d]咪唑-2-基)苯基 (TPBi)，45 nm/LiF (1 nm)/Al ( 100 nm)} 表现出良好的性能。掺杂双[2-(3,4,6-三氟苯基)吡啶](四苯基亚氨基二膦合)铱[Ir(F3,4,6ppy)2(tpip)](8 wt.-%)的器件表现出优异的性能，峰值电流效率 (ηc) 为 66.36 cd A-1，峰值外部量子效率 (ηext, EQE) 在 5.8 V 时为 25.7 %，最大功率效率 (ηp) 在 4.4 V 时为 48.20 lm W-1，以及最大亮度(Lmax) 在 12.6 V 时为 47627 cd m-2。值得注意的是，所有器件在相对高电流密度下的电致发光 (EL) 效率滚降效应非常温和，这有助于它们在亮度方面获得高效率。结果表明，这三种配合物，尤其是 [Ir(F3,4,6ppy)2(tpip)]，在 OLED 中有潜在的应用。