基于苯基喹啉配体修饰的铱磷光配合物及其高效纯红光有机电致发光器件

Iridium Phosphorescent Complexes Based on Modified Phenylquinoline Ligand and Their High-efficiency Pure Red Organic Electroluminescent Device

通过对2,4⁃2R⁃苯基⁃4⁃甲基喹啉主配体进行修饰,在苯基空间位阻较小的2位和4位引入供或吸电子能力的取代基(甲基,Me或甲氧基,MeO),分别合成了2种铱磷光配合物(2,4⁃2Me⁃mpq)_(2)Ir(acac)和(2,4⁃2MeO⁃mpq)_(2) Ir(acac),采用元素分析、核磁共振谱和单晶X射线衍射对其组成和化学结构进行了表征与确认。它们的光致发光光谱发射波长分别为610 nm和580 nm,光致发光量子产率分别为75%和80%,HOMO/LUMO能级差分别为2.04 eV和2.19 eV。以纯红光发射的磷光配合物(2,4⁃2Me⁃mpq)_(2)Ir(acac)为客体材料,制备了结构为ITO/TAPC(30 nm)/CBP∶(2,4⁃2Me⁃mpq)_(2)Ir(acac)(30 nm)∶x%/TPBi(30 nm)/Liq(2 nm)/Al的OLED器件,并优化了掺杂浓度,在10%的优化浓度下实现了高效红光OLED发光。器件的发射波长为607 nm,CIE坐标为(0.63,0.37),最大亮度为25980 cd/m^(2),电流效率为23.11 cd/A,外量子效率(EQE)高达20.28%。

Two iridium phosphorescent complexes were synthesized by using the modified 2,4-2R-phenyl-4-methylquinoline as the main ligands.Methyl or methoxy was introduced in the positions 2 and 4 with small steric hindrance of phenyl.Their compositions and chemical structures of the com⁃plexes were characterized by elemental analysis,nuclear magnetic resonance spectroscopy and sin⁃gle crystal X-ray diffraction.The(2,4-2Me-mpq)_(2)Ir(acac)and(2,4-2MeO-mpq)_(2)Ir(acac)with the photoluminescence quantum yields of 75%and 80%exhibit maximum emission peaks at 610 nm and 580 nm,respectively.The HOMO-LUMO energy levels difference of the two complexes are 2.04 eV and 2.19 eV,respectively.Using(2,4-2Me-mpq)_(2)Ir(acac)as the guest material,the high-efficiency pure red OLED with structure ITO/TAPC(30 nm)/CBP∶(2,4-2Me-mpq)_(2)Ir(acac)(30 nm)∶x%/TPBi(30 nm)/Liq(2 nm)/Al was prepared with different doping concentrations.At the optimal doping concentration of 10%,the device based on(2,4-2Me-mpq)_(2) Ir(acac)exhibited a red emission at 607 nm with CIE(0.63,0.37),a luminance of 25980 cd/m^(2),a maximum current effi⁃ciency of 23.11 cd/A and a maximum external quantum efficiency(EQE)of 20.28%,respectively.