Solution and Solid-State Characterization of Alq ₃-Functionalized Polymers

Poly(norbornene) has been functionalized with aluminum tris(8-hydroxyquinoline) (Alq₃), the emission and electron-transport layer of choice in organic light-emitting diodes. The resulting polymer can be spin coated onto surfaces thereby overcoming fabrication problems associated with pure Alq₃. The Alq₃-polymers, both in solution and in the solid-state, show outstanding emission properties, clearly indicating that the polymer backbone does not interfere with the optical properties of the pendant Alq₃ side-chain. The ligand sphere around the aluminum center on the polymer can be functionalized with electron-donating or -withdrawing groups, thereby allowing the emission of the polymer to be tuned from blue to yellow (430-549 nm). The results demonstrate the potential of the Alq₃-polymer system as emission layer in organic light-emitting diodes.