Spectrally camouflaged radiative pathway switching in all-inorganic perovskite derivatives for efficient optical encryption.

The growing demand for high-level information security necessitates advanced photonic materials with programmable, multidimensional optical responses. However, conventional research predominantly optimizes the performance of static, predefined luminescent centers, leaving the dopant-programmed switching of dominant radiative pathways largely unexplored. Herein, we propose and demonstrate a novel strategy of spectrally camouflaged switching of the dominant radiative pathway within CsCdCl3 perovskite microcrystals via a sequential Zr4+/Mn2+ doping protocol. Zr4+ initially acts as a structural modifier to tailor lattice strain and optimize self-trapped excitons (STEs) as an energy donor. The subsequent introduction of Mn2+ drives a highly efficient (with an apparent efficiency >97.6%) energy transfer, covertly shifting the dominant emission pathway from STE recombination to the Mn2+ 4T1→6A1 transition. While both the steady-state and persistent luminescence colors remain unchanged in the orange region, the internal quantum efficiency increases to 99.4%, accompanied by a fundamental reconfiguration of carrier dynamics. Exploiting this hidden photophysical transformation, we construct a dynamic optical information storage platform where the underlying luminescence mechanism itself serves as an invisible, advanced encryption dimension. This transition from conventional property tuning to mechanism programming establishes a robust material design principle for next-generation anti-counterfeiting technologies.