Stimuli‐Responsive Static Multimodal and Temporal Multicolor Luminescence Modulation in Lanthanide(III)/Manganese(II) Co‐Doped Cs ₂ NaLuCl ₆ Perovskites

Abstract Stimuli‐responsive materials that react to various external triggers are in high demand for advanced interactive photonic applications. Despite progress in the development of multi‐excitation‐capable luminescent materials, challenges remain in creating systems that exhibit both static multimodal and dynamic multicolor luminescence. Here, A novel class of luminescent materials is reported based on lanthanide(III) and manganese(II) co‐doped Cs 2 NaLuCl 6 double perovskite halides, which feature dynamic emission modulation under various excitation conditions and time scales, enabling multilevel anticounterfeiting and multidimensional optical encoding with temporally sensitive characteristics. Upon ultraviolet (UV), near‐infrared (NIR), X‐ray, and mechanical stimulation, the resulting materials exhibit versatile multimodal luminescence. Moreover, Mn 2+ doping‐induced multiple defect states endow the Cs 2 NaLuCl 6 :Mn 2+ /Er 3+ crystals with controllable persistent luminescence as well as adjustable thermal‐ and photo‐modulated luminescence, while Er 3+ incorporation enables tunable, dynamic multicolor emission through energy from Mn 2+ to Er 3+ . By utilizing spatial, spectral, temporal, and thermal controls, the perovskite‐based systems is presented to offer a flexible and robust security solution with enhanced resistance to replication. These findings hold great promise for next‐generation information encryption, providing high capacity, multifunctionality, and scalability, making them ideally suited for cutting‐edge optical security systems.