Effects of correlations on triplet loss processes in organic phosphorescent emission layers: Accurate and fast master equation modeling

Loss of triplet excitons by triplet-triplet annihilation (TTA) and triplet-polaron quenching (TPQ) is a major problem in modern organic light-emitting diodes with phosphorescent host-guest emission layers. Modeling of TTA and TPQ in these emission layers is therefore important. However, this modeling is complicated by positional correlations among the triplets and polarons. Kinetic Monte Carlo (KMC) simulations can account for these correlations, but are computationally expensive. In a previous paper [Taherpour, Phys. Rev. B 105, 085202 (2022)2469-995010.1103/PhysRevB.105.085202] we developed a master equation approach to modeling of TTA that accurately accounts for correlations, and is at the same time fast. In the present work, we extend the approach to include modeling of TPQ. We calculate the influence of TTA and TPQ on transient photoluminescence experiments and on steady-state emission efficiency, using KMC simulations as benchmark. We show that our extended master equation modeling is an accurate and fast alternative to KMC simulations.