Development of time-dependent Exciton diffusion solver for modeling Triplet-Triplet Fusion Mechanism in OLEDs

In this work, we developed a both stable and time-dependent exciton diffusion model including singlet and triplet exciton coupled with a modified Poisson & drift-diffusion solver to demonstrate the mechanism of triplet-triplet fusion (TTF) OLEDs. Using this modified simulator, we can demonstrate the characteristics of OLEDs including current-voltage curve, quantum efficiency performance, time-resolved electroluminescence spectrum, and electric profile...etc. Also, this solver can be used to explain the mechanism of hyper-TTF OLEDs, and analysis the loss from different exciton mechanism. Furthermore, we can do further optimization for TTF-OLEDs to achieve an internal quantum efficiency increasing of 23% (from 29% to 36%).