Trap-tuning in afterglow perovskite crystals through alkali metal ion doping.

Herein, we report a trap-tuning strategy involving alkali metal ions of Li + and K + , which enabled a fine tuning of afterglow traps at 250 K. Through Li + /K + doping, a red afterglow from Cs 2 AgInCl 6 :Mn was activated at room temperature, which was extended up to 3600 s at low temperature. Thermoluminescence measurement revealed a shallow trap at ∼0.50 eV below the conduction band, which could be shifted up- and down-ward by dopant species.