ELECTROLUMINESCENCE FROM DYSPROSIUM-CONTAINING AND NEODYMIUM-CONTAINING LB FILMS

In this paper we report on electroluminescence from Langmuir-Blodgett (LB) films of two navel molecular complexes originally developed for n on-linear optics applications containing neodymium and dysprosium triv alent rare earth ions. The two molecular complexes have a structure wh ich consists of a donor pi-pi conjugated cation ionically coupled to a complex anion consisting of a trivalent rare earth ion surrounded by four singly charged pyrazolone ligands. The two materials are identic al apart from the presence of either dysprosium or neodymium ions at t he centre of the complex anions. LB films of the complexes produced on glass/indium tin oxide substrates produce broad electroluminescence i n the visible region of the spectrum which is considerably red-shifted relative to their photoluminescence. The electroluminescent devices p repared operate in vacuo and at room temperature. The characteristic e missions associated with the rare earth ions themselves, observed as a result of photoexcitation, cannot be excited electrically.