Biscarbazole derivative host materials and green emitter for oled emissive region

Abstract

An organic electroluminescence device utilizes a novel combination comprising one or more biscarbazole derivative compounds as the phosphorescent host material in combination with a green phosphorescent dopant material in the light emitting region of the device, where the biscarbazole derivative compounds are represented by a formula (1A) or (1B) below; where Arepresents a substituted or unsubstituted nitrogen-containing heterocyclic group having 1 to 30 ring carbon atoms; Arepresents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or substituted or unsubstituted nitrogen-containing heterocyclic group having 1 to 30 ring carbon atoms; Xand Xeach are a linking group; Yto Yeach represent a substituent; p and q represent an integer of 1 to 4; and r and s represent an integer of 1 to 3; and the green phosphorescent dopant material is a phosphorescent organometallic complex having a chemical structure represented by LL'L″M wherein M is a metal that forms octahedral complexes, L, L′, and L″ are equivalent or inequivalent bidentate ligands wherein each L comprises a substituted or unsubstituted phenylpyridine ligand coordinated to M through an sphybridized carbon and N; and, one of L, L′ and L″ is different from at least one of the other two.