Universal Display Corporation
ORGANIC ELECTROLUMINESCENT COMPOUNDS AND DEVICES

Abstract:

A compound having a formula M(L.sub.A).sub.x(L.sub.B).sub.y(L.sub.C).sub.z is provided. In the compound of M(L.sub.A).sub.x(L.sub.B).sub.y(L.sub.C).sub.z, ligand L.sub.A is ##STR00001## ligand L.sub.B is ##STR00002## and ligand L.sub.C is ##STR00003## In addition, M is a metal having an atomic mass greater than 40, x is 1, 2, or 3, and y and z are independently 0, 1, or 2. In the compound, Z.sup.5 is carbon or nitrogen; one of Z.sup.1 to Z.sup.4 is nitrogen and three of Z.sup.1 to Z.sup.4 are carbon substituted by R.sup.B, and rings C and D are each independently a 5 or 6-membered carbocyclic or heterocyclic ring. Each R.sup.A, R.sup.B, R.sup.C, and R.sup.D is independently selected from a group of substituents, where at least one R.sup.B is heteroaryl, which can be further substituted, and any adjacent substitutents are optionally joined or fused into a ring. Formulations and devices, such as OLEDs, that include the first compound are also provided.