Journal Article Research Support, Non-U.S. Gov't Coordination Complexes FIrpic Ir complex OLED Organic light-emitting diodes (OLEDs) Pt complex Review TADF ancillary ligands bis((4,6-difluorophenyl)pyridinato-N,C(2'))iridium(III)picolinate blue phosphorescent OLED delayed fluorescence device lifetimes dipole orientation energy transfer exciplex exciplex forming co-host exciplex forming co-hosts exciplexes fluorescent dyes fluorescent organic light-emitting diodes iridium complexes map of maximum achievable EQE organic light-emitting diodes (OLEDs) orientation of transition dipole oriented crystals phosphorescent phosphorescent OLEDs