Ionic Liquid‐Assisted One‐Step Large‐Scale Synthesis of Cs₂ZrCl₆:CDs Composites with Tunable Multicolor Afterglow Emission

Abstract The strategy of utilizing all‐inorganic lead‐free perovskites as the matrix to form synergies with complementary functional nanomaterials has attracted great interest. In this study, a simplified one‐pot method that is employed to combine carbon dots with the all‐inorganic perovskites Cs₂ZrCl₆ to form a novel nano/microstructured composite is reported. The abundant functional groups on the surface of the carbon dots can effectively form coordination bonds with the Zr⁴⁺ ions in Cs₂ZrCl₆, realizing the effective dispersion of the carbon dots in the matrix. The composite not only introduces a synergistic interaction between carbon dots and Cs₂ZrCl₆, but also exhibits novel afterglow emission. This afterglow emission arises from the synergistic immobilization of triple excitons in a 3D spatially confined and rigid environment, thereby suppressing non‐radiative excitation processes. Tunable afterglow emission over the entire spectral range is achieved through control of the carbon source reactants, highlighting the outstanding versatility of this composite approach. This composite exhibits dual‐mode fluorescence and afterglow emission, holding tremendous potential for applications in information encryption and anti‐counterfeiting.