Fig. 1. (a) Molecular design principle. The luminophore and heavy atom/group are linked by a flexible chain. (b) Molecular stacking of carbazole in crystals, and the reason for strong fluorescence and detectable persistent phosphorescence with a lifetime of 540 ms is because of weak spin–orbit coupling. (c) Molecular structures of CCnBr and CCnPhBr and a description of persistent phosphorescence induced by an intermolecular moderate heavy atom effect. (d) Photos of crystals under 365 nm light with fluorescence and phosphorescence quantum yields and average lifetimes for phosphorescence.
