Dual‐Mode Afterglow of Organic–Inorganic Hybrid Metal Halides for Multi‐Dimensional Information Encryption

Abstract Organic and organic–inorganic hybrid materials exhibiting room‐temperature phosphorescence (RTP) and long persistent luminescence (LPL) materials have attracted growing attention for various time‐resolved optoelectronic applications. To date, realizing intrinsically distinct RTP and LPL emissions within a single material system remains elusive, yet it is crucial for unlocking multifunctional applications such as multilevel optical encryption. Here, a Mn 2+ ‐doped organic–inorganic hybrid metal halide is presented that exhibits bright yellow phosphorescence under UV excitation and a long‐lasting red afterglow persisting for over 600 s under X‐ray irradiation. These contrasting emission behaviors originate from distinct recombination pathways: triplet exciton emission from the organic ligand governs RTP, while LPL arises from Mn 2+ ‐centered emission. The latter is enabled by the thermally activated release of charge carriers trapped at radiation‐induced defects. This excitation‐dependent divergence in luminescence offers temporal and spectral control over optical signals, enabling a multidimensional time–space–energy encoded optical encryption platform. The findings introduce a pathway‐engineered strategy for multi‐mode phosphorescent materials, paving the way for further materials design for emerging intelligent optoelectronic devices.