Solution and Solid-State Characterization of Alq3-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.