Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA.
Chemistry. 2011 Aug 8;17(33):9076-82. doi: 10.1002/chem.201100707. Epub 2011 Jul 21.
Combinations of electron-withdrawing and -donating substituents on the 8-hydroxyquinoline ligand of the tris(8-hydroxyquinoline)aluminum (Alq(3)) complexes allow for control of the HOMO and LUMO energies and the HOMO-LUMO gap responsible for emission from the complexes. Here, we present a systematic study on tuning the emission and electroluminescence (EL) from Alq(3) complexes from the green to blue region. In this study, we explored the combination of electron-donating substituents on C4 and C6. Compounds 1-6 displayed the emission tuning between 478 and 526 nm, and fluorescence quantum yield between 0.15 and 0.57. The compounds 2-6 were used as emitters and hosts in organic light-emitting diodes (OLEDs). The highest OLED external quantum efficiency (EQE) observed was 4.6%, which is among the highest observed for Alq(3) complexes. Also, the compounds 3-5 were used as hosts for red phosphorescent dopants to obtain white light-emitting diodes (WOLED). The WOLEDs displayed high efficiency (EQE up to 19%) and high white color purity (color rendering index (CRI≈85).
在三(8-羟基喹啉)铝(Alq(3))配合物的 8-羟基喹啉配体上引入吸电子和供电子取代基的组合可以控制 HOMO 和 LUMO 能量以及 HOMO-LUMO 能隙，从而影响配合物的发光。在这里，我们系统地研究了通过调整电子供体取代基在 C4 和 C6 上的位置来调节 Alq(3)配合物从绿光到蓝光区域的发射。在这项研究中，我们探索了在 C4 和 C6 上引入供电子取代基的组合。化合物 1-6 的发射波长在 478nm 到 526nm 之间可调，荧光量子产率在 0.15 到 0.57 之间可调。化合物 2-6 被用作有机发光二极管(OLED)的发射体和主体。观察到的最高 OLED 外量子效率(EQE)为 4.6%，这在 Alq(3)配合物中属于较高水平。此外，化合物 3-5 还被用作红色磷光掺杂剂的主体，以获得白光发光二极管(WOLED)。WOLED 显示出高效率(EQE 高达 19%)和高的白光色纯度(显色指数(CRI≈85))。
