LED characterization of an alternating copolymer and its blends

Abstract

Soluble light-emissive alternating copolymers based on alkylfluorene and bis-phenylenevinylene were synthesized using Wittig coupling reaction. The PL and EL efficiency of emissive polymers increased in the blends diluted with non-emissive polymer such a PVK. The emission spectrum of the blends also became narrower than that of emissive polymer only due to the reduction of intermolecular excimer formation. The blends of emissive polymers with different band-gap energies were investigated in terms of energy transfer mechanism. The characteristics of emissive polymer with lower band-gap energy dominates the PL and EL spectrum of blends. The quantum efficiency in the order of 0.025% was obtained the electrodes of ITO and aluminum.