Facile ball-milling synthesis of highly efficient manganese halides toward white light-emitting display and X-ray imaging

Organic-inorganic hybrid Mn(II) halides have garnered considerable attention for various optoelectronic applications due to their environmental friendliness and high photoluminescence quantum yield (PLQY), which stems from the d-d characteristic transition (⁴T₁(G) → ⁶A₁) of Mn²⁺. However, the complex synthesis process restricts this material’s potential for low-cost, large-scale production, thereby impeding its further development. In this study, the Mn(II) halide (C₂₂H₂₂O₂P)₂MnBr₄ was synthesized via a simple and efficient mechanochemical ball-milling approach, achieving high photoluminescence efficiency and production yield. The halide exhibits intense green emission centered at 520 nm with a PLQY of up to 96.1%. Combined experimental and theoretical characterizations confirm that the strong light emission originates from the synergistic interaction between organic cations and inorganic framework components. Accordingly, a white light-emitting diode (WLED) device based on (C₂₂H₂₂O₂P)₂MnBr₄ was fabricated, exhibiting bright white light emission and a wide color gamut of 113% NTSC. Furthermore, a scintillation screen based on (C₂₂H₂₂O₂P)₂MnBr₄ was fabricated and utilized to investigate the internal structures of various objects. The screen demonstrates a high relative light yield of 70546 photons MeV⁻¹, a low detection limit of 33.8 nGy_air s⁻¹, and a spatial resolution of up to 12.36 lp mm⁻¹. Finally, by integrating the scintillation screen with a thin-film transistor (TFT) backplane, the resulting X-ray detector successfully enables simulated medical imaging of dental caries. This work not only establishes a robust foundation for the large-scale synthesis of highly efficient luminescent Mn(II) halides but also highlights their potential in multifunctional light-emitting applications.