LAUSR

A detailed optical and electrical investigation of a blue thermally activated delayed fluorescence (TADF)‐based organic light emitting diode (OLED) is performed by drift‐diffusion simulations. Calculation of the charge transport of the different carrier populations in the device is used to predict and investigate the current–voltage characteristics and the resulting internal radiative emission profile. The explicit modeling of both singlet and exciton states of the TADF emitter combined with the inclusion of proper models for band‐to‐band transitions, bimolecular recombination mechanisms, and intersystem crossing allows to investigate the kinetics of fluorescence by thermal activation. The investigation provides insights into the role of triplet–triplet annihilation and triplet–polaron quenching for the roll‐off in internal quantum efficiency.