Photodynamics and Performance Metrics in Cavity-Coupled OLEDs: A Unified Quantum Master Equation Approach

Abstract: Controlling light-matter interactions is emerging as a powerful strategy to enhance the performance of organic light-emitting diodes (OLEDs). By embedding the emissive layer in planar microcavities or other modified optical environments, excitons can couple to photonic modes, enabling new regimes of device operation. In the weak-coupling regime, Purcell-enhanced emission can accelerate radiative decay, while in the strong-coupling regime, excitons and photons hybridize to form entirely new energy eigenstates with altered dynamics. These effects offer potential solutions to key challenges in OLEDs, such as triplet accumulation and efficiency roll-off, yet demonstrations in the strong-coupling case remain sparse and modest. To systematically understand and optimize photodynamics across the different coupling regimes, we develop a unified quantum master equation model for cavity-coupled (and uncoupled) OLEDs. We apply this model to evaluate device performance and explore how photonic environments can be engineered for triplet harvesting, enhanced emission, and beyond.