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

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.