Ultralong Room‐Temperature Phosphorescence from Organic–Inorganic Hybrid Perovskitoid Based on Metal‐Organic Complex Component

Abstract Organic–inorganic hybrid perovskite or perovskitoid phosphorescent materials have aroused extensive research interests due to their applications in organic light emitting diodes, anti‐counterfeiting, display, and other fields. Herein, a new strategy is proposed, employing metal‐organic complex (MOC) cations as the organic components, which can increase the spin–orbit coupling (SOC) and intersystem crossing (ISC) efficiencies of the organic units, and hybrid with inorganic parts to form a novel type MOC–inorganic composed perovskitoid. In detail, a lead‐free MOC–inorganic perovskitoid material, named P‐Cl, is synthesized by self‐assembly of preassembled MOC from metallized crown ethers with inorganic cadmium halide component. In the solid state, the assembled perovskitoid exhibits a tunable fluorescence color from blue to green, during which a cold white light emission is achieved. Interestingly, after removal of the radiation source, the perovskitoid still emits a bright and color‐tunable long persistent luminescence (LPL) from cyan to green. Single‐crystal X‐ray diffraction analysis and theoretical calculations reveal that the bright LPL of P‐Cl arises from the improvement of the metal‐organic part to increase the SOC and the interlocking of metal halogenated layers to inhibit the nonradiative transition. The proposed strategy not only broadens the range of organic–inorganic perovskitoid hybrid materials but also facilitates the design of multifunctional LPL materials.