Exciton Binding Energy of Phosphorescent Emitter Molecules in Organic Light‐Emitting Diodes

ABSTRACT In phosphorescent organic light‐emitting diodes (OLEDs), which are commonly used in display applications, metal–organic emitter molecules are usually blended at a small concentration in a host material. Their efficiency and operational lifetime depend strongly on the energies of the highest occupied molecular orbital , the lowest unoccupied molecular orbital , and the triplet exciton binding energy of the emitter materials. However, determining and remains a challenge. In this work, a methodology is demonstrated for determining of iridium‐based phosphorescent emitters from field‐induced dissociation experiments, and for using this energy to determine . The consistency of the analysis method, which makes use of kinetic Monte Carlo simulations, is demonstrated by a variation of the host materials and the blend composition, and by providing a comparison with quantum‐chemical calculations. The binding energy of triplet excitons in Ir‐based phosphorescent emitters is found to lie typically in the range of 1.0–1.3 eV.