Abstract
A brief review is given on the unique features of thermally activated delayed fluorescence (TADF). We demonstrate a novel pathway to open an ultimate electroluminescence (EL) efficiency by using simple aromatic compounds displaying efficient TADF molecules. We found that a proper design of organic molecules enables the formation of a small energy gap between singlet and triplet excited states, resulting in the enhanced T1 to S1 reverse intersystem crossing. We also demonstrate a novel pathway for highly efficient fluorescence-based light-emitting diodes by applying the concept of TADF as an exciton generation source.
