1 Introduction Pioneering research by Hatakeyama and co-worker in 2016 presented co-doping electron-rich/-deficient atoms into polycyclic aromatic hydrocarbons (PAHs), resulting in frontier orbitals alternatively centered in electron-rich/-deficient atoms and their respective resonant atoms.[1] This approach successfully narrows the energy offset of S1 and T1 states, leading to thermally activated delayed fluorescence in PAHs. Thus, these PAHs are named multi-resonant (MR-TADF) emitters.[2,...
