Tailoring Coordination Environment in Organic‐Inorganic Hybrid Manganese Halide Glass Toward Color‐Tunable Emission

ABSTRACT Organic–inorganic Mn(II)‐based hybrid halides have garnered significant attention in optoelectronic applications. Most of their emission is restricted to green or red, while the expansion of emission modulation range presents a major difficulty and the underlying mechanism is not yet fully understood. Herein, we design the synthesis of a series of hybrid Mn halides glass by varying the molar ratio of organic RTPBr (R = Pentyl, Ethyl, Heptyl or Benzyl; TP = (triphenyl)phosphonium) and inorganic MnBr 2 ·4H 2 O via the melt‐quench method to achieve luminescence tuning between 525 and 609 nm. This luminescence tuning phenomenon is exclusive to disordered glass phases and absent in their crystalline counterparts. This luminescence shift originates from the modification of the internal coordination environment of the glass, induced by the reduced organic content. Concurrently, temperature‐dependent photoluminescence reveals that the 1:1 glass possesses a high Huang–Rhys factor (S), which may be associated with self‐trapped excitons. The highest photoluminescence quantum yield (PLQY) of the synthesized glass was achieved up to 94.79%. This work provides a method for tuning the intermediate band gap from green to red in hybrid Mn halides. Concurrently, the glass exhibits excitation wavelength‐dependent emission in selected compositions, offering a fresh insight for luminescent materials in information storage.