Universal Display Corporation
ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES

Abstract:

A compound including a first ligand L.sub.A having the structure of Formula I, ##STR00001## is disclosed. In Formula I, rings A and B are each a 6-membered rings; Z.sup.1 and Z.sup.2 are each carbon or nitrogen; each R.sup.A and R.sup.B is independently hydrogen or a variety of substituents; any two substituents are optionally joined or fused into a ring; at least one R.sup.A or R.sup.B comprises an aromatic group substituted by a bridge structure, and this R.sup.A or R.sup.B joins with an adjacent substituent and fuses to ring A or B; the bridge structure comprises a backbone structure that forms a fused first ring; the backbone structure is saturated, comprises at least one heteroatom, and is optionally further substituted; and the ligand L.sub.A is coordinated to a metal M that can be coordinated to other ligands.