Biscarbazole derivative host materials for oled emissive region

Abstract

An organic electroluminescence device utilizes a novel combination of one or more biscarbazole derivative compounds as the phosphorescent host material in combination with an organometallic phosphorescent material as a dopant in the light emitting region of the device, where the biscarbazole derivative compounds are represented by a formula (1A) or (2A) 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 organometallic phosphorescent material is a compound having a substituted chemical structure represented by the formula (4A): where each R is independently selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF, CF, trifluorovinyl, COR, C(O)R, NR, NO, OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group; M is a platinum group metal; Ar', Ar″, Ar′″ and Ar″″ each independently represent a substituted or unsubstituted aryl or heteroaryl substituent on the phenylpyridine ligand; a is 0 or 1; b is 0 or 1; c is 0 or 1; d is 0 or 1; m is 1 or 2; n is 1 or 2; m+n is the maximum number of ligands that can be coordinated to M, and wherein at least one of a, b, c, and d is 1 and when at least one of a and b is 1 and at least one of b and c is 1, at least one of Ar′ and Ar″ is different from at least one of Ar′″ and Ar″″.