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

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 Cs₂NaLuCl₆ 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, Mn²⁺doping-induced multiple defect states endow the Cs₂NaLuCl₆:Mn²⁺/Er³⁺ crystals with controllable persistent luminescence as well as adjustable thermal- and photo-modulated luminescence, while Er³⁺ incorporation enables tunable, dynamic multicolor emission through energy from Mn²⁺ to Er³⁺. 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.