Highly Efficient and Ultralong Afterglow Emission with Anti‐Thermal Quenching from CsCdCl3 : Mn Perovskite Single Crystals

Triplet exciton-based long-lived phosphorescence is severely limited by the thermal quenching at high temperature. Herein, we propose a novel strategy based on the energy transfer from triplet self-trapped excitons to Mn2+ dopants in solution-processed perovskite CsCdCl3 . It is found the Mn2+ doped hexagonal phase CsCdCl3 could simultaneously exhibit high emission efficiency (81.5 %) and long afterglow duration time (150 s). Besides, the afterglow emission exhibits anti-thermal quenching from 300 to 400 K. In-depth charge-carrier dynamics studies and density functional theory (DFT) calculation provide unambiguous evidence that carrier detrapping from trap states (mainly induced by Cl vacancy) to localized emission centers ([MnCl6 ]4- ) is responsible for the afterglow emission with anti-thermal quenching. Enlightened by the present results, we demonstrate the application of the developed materials for optical storage and logic operation applications.