Thermally activated delayed fluorescence (TADF) emitters have been widely investigated in organic light-emitting diodes (OLEDs) and to a lesser extent in lightemitting electrochemical cells (LECs). A conventional TADF molecule contains electron donor (D) and acceptor (A) groups that are weakly electronically conjugated. This is due to the presence of a large dihedral angle between the two that results in a weak overlap between highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbital (LUMO). The resulting small singlet-triplet energy gap (ΔEST) provides an avenue to harvest 100% of the electrically generated excitons in the device through reverse intersystem crossing (RISC) prior to emission from the S1 state. However, due to the large degree of structural relaxation in the S1 state as a result of its long-range charge transfer (LRCT) character, the emission of D-A type compounds is broad, leading to poor color saturation.