Improved stability of solid state light emitting electrochemical cells consisting of ruthenium and iridium complexes

ABSTRACTTwo charged organometallic complexes containing bulky hydrophobic ligands based on ruthenium (II) and iridium (III) were synthesized and their performance in solid state light emitting electrochemical cells is described. The complexes were chosen as due to their large ligands a diminished susceptibility towards the formation of destructive complexes during device operation is expected. The LEC device performances reveal the longest living devices reported so far under dc bias. Quantum chemical calculations confirm that the major effect of the bulky diphenylphenanthroline ligands is of steric origin and not related with changes in the molecular electronic structure of the complexes.