These are rigid polycyclic aromatic hydrocarbons that are typically doped with both electronrich and electron-deficient groups. Suitable regiochemistry of these p-and n-dopants produces an alternating pattern of increasing and decreasing electron density in the excited state as compared to the ground state, leading to the necessary small exchange energy that turns on TADF. Given the short distance between D and A motifs, the emissive excited state is of short range CT (SRCT) character. Compared to D-A TADF compounds, MR-TADF emitters have more intense low energy absorption bands, narrower emission spectra, smaller Stokes shifts, and their emission spectra show only minimal positive solvatochromism, all potentially attractive properties for their use as PCs. Our group has demonstrated the broad utility of two families of MR-TADF PCs in a range of photoinduced electron transfer (PET) and PEnT reactions. These two families contained nitrogen donor atoms and either boron or carbonyl groups as n-dopants within the polycyclic aromatic hydrocarbon framework.