Quantum efficiencies of electroluminescent poly(p-phenylenes)

Summary form only given. Poly(paraphenylene) (PPP) and some derivatives (ladder polymers) have proved to be suitable materials for electroluminescence devices. Photoluminescence and electroluminescence measurements require the preparation of homogenous thin films. They are obtained by spincoating of soluble material (precursor PPP and ladder-type PPP) or evaporation of low molecular weight oligophenyls. We present recent results on quantum efficiency and the electronic structure of these materials used as the active layer in electroluminescence devices. The influence of the molecular geometry and intermolecular effects on the emission- and excitation- spectrum as well as on the quantum efficiency (photo- and electroluminescence) is pointed out. The financial support of this research project by the Volkswagen Stiftung is gratefully acknowledged.