Green Light-Emitting Solid-State Electrochemical Cell Obtained from a Homoleptic Iridium(III)Complex Containing Ionically Charged Ligands

摘要

Organic light-emitting diodes (OLEDs)are becoming increasingly successful as a new display technology.Light-emitting electrochemical cells (LECs)are among the youngest generation of OLEDs and contain ionic charges as additional ingredients.These ionic charges facilitate electronic charge injection into the light-emitting film independent of the metallic electrode employed.First examples of LECs were based on polymeric OLEDs,to which salts,such as LiCF_3,were added to facilitate the charge injection.Later examples used a single molecule approach,in which a single molecule acts both as the charge transporting species and as the emitter.Most of these single molecule type LECs make use of the positively charged metal organic complex,tris-bipyridine ruthenium,balanced by a large negative counterion such as hexafluorophosphate.