Universal Display Corporation
Organic electroluminescent materials and devices

Abstract:

A compound that has the structure according to Formula M(L.sub.A).sub.x(L.sub.B).sub.y(L.sub.C).sub.z is disclosed. In Formula 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## and OLEDs and formulations containing these compounds are disclosed. In Formula M(L.sub.A).sub.x(L.sub.B).sub.y(L.sub.C).sub.z: M is a metal; x is 1 or 2; X.sup.1-X.sup.4 and A.sup.1-A.sup.8 are C or N; at least one of A.sup.1-A.sup.8 is N; X is O, S, or Se; two adjacent R.sup.B form a six-member aromatic ring E fused to ring B; and each R.sup.A-R.sup.E and R.sup.1-R.sup.4 is independently hydrogen or a substituent.