The condition for electroplex emission from an europium complex doped poly(N-vinylcarbazole)

Spectral characteristics of photoluminescence (PL) and electroluminescence (EL) of poly(N-vinylcarbazole) (PVK) matrices doped with a novel europium complex Eu(aspirin)3phen were investigated. A red-shift and broadening were observed in the EL spectra but not in the PL ones. However, neither red-shift nor broadening were observed in the EL spectra of PVK doped with a similar complex with the same ligand, terbium complex (Tb(aspirin)3phen). This result suggests the formation of electroplexes in blend systems, which is likely due to inefficient energy transfer from host molecules to dopant molecules.