Reduced Operating Voltages in Polymer Light-Emitting Diodes Doped with Rare-Earth Complexes


  • The authors are grateful to the National Science Foundation (CHE-0098240 and ECS-0093502) for financial assistance. JCO is a Kodak Fellow.


Light-emitting diodes (LEDs) were fabricated using two europium complexes, differing only by the addition of tert-butyl groups around the β-diketonate ligands (see Figure), blended into poly(2-(6′-cyano-6′-methyl-heptyloxy)-1,4-phenylene) (CN-PPP). The addition of tert-butyl groups results in CN-PPP–Eu LEDs with increased operational lifetime and decreased operating voltage.