Universal Display Corporation
ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES

Abstract:

Provided are compounds having a first ligand L.sub.A of Formula I ##STR00001## where, R and R.sup.A each represents mono to the maximum allowable substitutions, or no substitution; Z.sup.1 to Z.sup.4 are each independently C or N; at least two adjacent Z.sup.1 to Z.sup.4 are C and the corresponding R groups attached to them form a structure of Formula II ##STR00002##