Manganese-Doped Low-Dimensional Cadmium Halide for Excitation-Dependent Multicolor Emitting

Low-dimensional metal halides (LDMHs) have emerged as perovskite-derived luminescence materials in solid-state lighting and display. However, serious thermal quenching effects and water instability remain formidable challenges. Herein, we demonstrate a facile manganese-doping strategy toward cadmium-based LDMH to simultaneously realize high water- and thermal-stable excitation-dependent luminescence. Through a small amount of Mn²⁺ doping, one-dimensional (1D) [C₁₀H₉ClN]CdCl₃:<i>x</i>Mn (<i>x</i> = 0.06%-5.06%) shows highly efficient red luminescence with enhanced photoluminescence quantum yield (PLQY) above 34%. Benefiting from the dual emitting states, these Mn²⁺-doped halides display adjustable excitation-dependent multicolor luminescence output from green to white to red light emission. In addition, π···π stacking interaction between parallel organic cations and robust inorganic frameworks effectively prevents thermal quenching and water decomposition. This work provides a rational luminescence optimization strategy at a high-temperature aqueous phase, realizing adjustable multicolor luminescence with the potential application of light-emitting diodes and anticounterfeiting. A new Mn²⁺-doped [C₁₀H₉ClN]CdCl₃ halide displays highly efficient excitation wavelength-dependent multicolor luminescence, showcasing advanced applications in anticounterfeiting and information security. Furthermore, these doped halides demonstrate robust intrinsic structural and optical stability, remaining stable even after prolonged exposure to water and high temperatures. This characteristic opens new avenues for the rational design of high-performance luminescent materials.