Intrinsic defective long-persistent luminescence from organic-inorganic hybrid halide perovskite for multiple information encryption

As result of spin-forbidden transition for triplet exciton, the afterglow lifetime of OIHPs was limited to a few seconds. Herein, color-tunable emissions and LPL at room temperature are successfully achieved in (C4H6N3O)2InCl5·H2O OIHP. The prepared (C4H6N3O)2InCl5·H2O exhibit three distinct emissions peaks at 400 nm, 450 nm, and 480 nm, which are revealed from the dynamic transformation from the keto form to the enol from through the ESIPT process. Notably, the (C4H6N3O)2InCl5·H2O singe crystals perform green LPL with a long duration of 15000 s at room temperature. In-depth theoretical calculations and experimental studies suggest that intrinsic defects of (C4H6N3O)2InCl5·H2O introduce trap states that store the charge carrier and release them to the triplet state of organic components of (C4H6N3O)2InCl5·H2O to achieve LPL. This work offers a valuable method for increasing LPL duration for its triplet exciton in OIHPs by introducing intrinsic defective. Finally, the good stability and optical information encryption application of (C4H6N3O)2InCl5·H2O are demonstrated.