Measurement and simulation of exciton decay times in organic light-emitting devices with different layer structures

The decay time of an exciton depends on the coupling between the dipole oscillator and the optical environment in which it is placed. For an organic light-emitting device this environment is determined by the thin-film layer structure. The radiative decay competes with nonradiative decay channels and in this way influences the luminescent efficiency and the external quantum efficiency of the device. We describe a method to estimate the dependency of the exciton decay time and the luminescent efficiency on the thin-film stack and validate the results experimentally.