氮杂环苯基吡啶类铱配合物合成及器件性能

Synthesis and device properties of azeticyclic phenylpyridine iridium complexes

摘要:

通过对2-甲基-8-(2-吡啶基)苯并呋喃[2,3-B]吡啶辅助配体进行修饰,在吡啶的4号位引入吸电子基团苯基,并对其进行全氘代,同时对5-甲基-2-对甲苯基吡啶主配体的两个甲基进行全氘代,分别合成了两种铱磷光配合物Ⅳ和Ⅳ-d₂₀,采用元素分析、质谱和核磁共振氢谱对其结构进行了表征与确认。利用UV-Vis 光谱、荧光发射光谱(PL)和循环伏安法对其光物理性质及能级结构进行了研究。结果表明：铱配合物的Ⅳ和Ⅳ-d₂₀光致发光光谱发射波长分别为546.85nm和548nm；它们的HOMO和LUMO能级分别为-5.237ev和-2.645ev、-5.082ev和-2.50ev,都是潜在的黄绿色磷光材料。以铱配合物Ⅳ和Ⅳ-d₂₀为客体,制备了结构为ITO/HT:NDP-9(100nm,2%)/HT(130nm)/EB(10nm)/GH:化合物Ⅳ或Ⅳ-d₂₀(40nm,5%)/HB(10nm)/ ET:Liq(35nm,50%)/Liq(10nm)/Al(150nm)的OLED器件,并研究了它们的器件性能。结果表明：铱配合物Ⅳ-d₂₀表现出更优异的器件性能。电流密度为20mA/cm₂^时,铱配合物Ⅳ-d₂₀的器件发射波长为552nm,CIE 坐标为 (0.422,0.569),电流效率为 87.00cd/A,外量子效率(EQE)高达23.82%。

Abstract:

Two iridium phosphorescent complexes IV and IV.-d₂₀ were synthesized by modifying the 2-methyl-8-(2-pyridyl)benzofuran[2,3-B]pyridine auxiliary ligand, introducing electron-absorbing group phenyl at the 4th position of pyridine, and fully deuterated the two methyl groups of the 5-methyl-2-p-tolylpyridine main ligand, and characterizing and confirming their structures by elemental analysis, mass spectrometry and nuclear magnetic resonance hydrogen spectroscopy. The photophysical properties and energy level structure were studied by UV-Vis spectroscopy, fluorescence emission spectroscopy (PL) and cyclic voltammetry. The results showed that the emission wavelengths of IV and IV-d₂₀ photoluminescence spectra of iridium complexes were 546.85nm and 548nm, respectively, and their HOMO and LUMO energy levels were -5.237ev and -2.645ev, -5.082ev and -2.50ev, respectively, which were potential yellow-green phosphorescent materials. OLED devices with the structure of ITO/HT:NDP-9(100nm, 2%)/HT(130nm)/EB(10nm)/GH:compound IV or IV-d₂₀(40nm, 5%)/HB(10nm)/ET:Liq (35nm, 50%)/Liq(10nm)/Al (150nm) were prepared with iridium complexes IV and IV-d₂₀/HB(10nm)/ET:Liq (35nm, 50%)/Liq(10nm)/Al(150nm), and their device performance was studied. The results showed that iridium complex IV-d₂₀ showed better device performance. At a current density of 20mA/cm₂^{, the device of iridium complex IV-d}₂₀ emits at a wavelength of 552nm, a CIE coordinate of (0.422, 0.569), a current efficiency of 87.00cd/A, and an external quantum efficiency (EQE) of 23.82%.