Effective Color Tuning in Organic Light-Emitting Diodes Based on Aluminum Tris(5-aryl-8-hydroxyquinoline) Complexes

摘要

The photophysical properties and electroluminescence of a series of tris(8-quinolinolate)Al~Ⅲ compounds with substituted aryl moieties in the 5-position are described. It was shown that the substituent electronic effects, when projected to the quinolinolate chromophore via an aromatic spacer, provide an effective tool for remarkable systematic emission-color tuning of both the PL and EL over a range of about 300 nm (450-800 nm). The devices fabricated using complexes 1a-1k displayed strong EL, suggesting that this approach could generate potentially useful OLED materials. The correlation between the electronic nature of the aryl substituents, HOMO-LUMO gap, and the emissive properties of the complexes, suggests that this strategy may be used to predict the properties of new/future electroluminescent materials. The successful tuning of HOMO-LUMO energies is also expected to affect the electron mobility in these materials. Studies to this effect are the subject of ongoing research.