International Conference on Solid State Devices and Materials

Long-persistent luminescence (LPL) in materials, particularly inorganic metal oxides, occurs due to charge carriers generated by light absorption that are trapped and gradually released by thermal energy. In organic materials, charge separation can occur through intermolecular charge transfer excited states, enabling long-term charge storage. This mechanism involves careful selection of donor and acceptor molecules and introducing charge trap materials to stabilize charges. Recombination of stored charges results in emission, which in organic systems often includes thermally activated delayed fluorescence (TADF). Stimulus-responsive emission, both thermal and photo-stimulated, can be used to probe and enhance these luminescent properties, as demonstrated in the mMTDATA/PPT/Rubrene system.