An OLED device comprises a cathode, an anode, and has therebetween a light emitting layer comprising a phosphorescent emitter represented by Formula (I): L.sub.nM (I) wherein each L is a cyclometallated ligand with at least one containing a coumarin group, M is Ir or Pt, and n is 3 when M is Ir and 2 when M is Pt. The invention also comprised the compound of formula (I).