Universal Display Corporation
Organic electroluminescent materials and devices

Abstract:

A compound including a ligand having the formula: ##STR00001## or ##STR00002## is disclosed. In these formulas, each R.sub.1, R.sub.2, and R.sub.3 is independently selected from hydrogen, alkyl, and aryl; at least one of R.sub.1 and R.sub.2 is a branched alkyl containing at least 4 carbon atoms, where the branching occurs at a position further than the benzylic position; where R.sub.1 and R.sub.3 are mono-, di-, tri-, tetra-, or no substitutions; and R.sub.2 is mono-, di-, or no substitutions. Heteroleptic iridium complexes including such compounds, and devices including such compounds are also disclosed.