Versatile Molecular Functionalization for Inhibiting Concentration Quenching of Thermally Activated Delayed Fluorescence

Concentration quenching of thermally activated delayed fluorescence is found to be dominated by electron‐exchange interactions, as described by the Dexter energy‐transfer model. Owing to the short‐range nature of the electron‐exchange interactions, even a small modulation in the molecular geometric structure drastically affects the concentration‐quenching, leading to enhanced solid‐state photoluminescence and electroluminescence quantum efficiencies.