| 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: (1A), (2A) where A 1 represents a substituted or unsubstituted nitrogen-containing heterocyclic group having 1 to 30 ring carbon atoms; A 2 represents 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; X i and X 2 each are a linking group; Y 1 to Y 4 each 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 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , 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"". |