Excitation‐Selective and Double‐Emissive Lead‐Free Binary Hybrid Metal Halides for White Light‐Emitting Diode and X‐Ray Scintillation

Zero-dimensional (0D) organic metal halides comprising heterogeneous metal cations in single phase can achieve multiple luminous emissions enabling them toward multifunctional light-emitting applications. Herein, A novel single crystal of (C8 H20 N)4 SbMnCl9 containing two luminescent centers of [SbCl5 ]2- pentahedrons and [MnCl4 ]2- tetrahedrons is reported. The large distance between Sb-Sb, Mn-Mn, and Sb-Mn as well as theory calculation indicate negligible interaction between individual centers, thus endowing (C8 H20 N)4 SbMnCl9 with excitation-dependable and efficient luminescence. Under near-UV excitation, only orange emission originates from self-trapped excitons recombination in [SbCl5 ]2- pentahedron occurs with photoluminescence quantum yield (PLQY) of 91.5%. Under blue-light excitation, only green emission originating from 4 T1 -6 A1 transition of Mn2+ in [MnCl4 ]2- tetrahedrons occurs with PLQY of 66.8%. Interestingly, upon X-ray illumination, both emissions can be fully achieved due to the high-energy photon absorption. Consequently, (C8 H20 N)4 SbMnCl9 is employed as phosphors to fabricate white light-emitting diodes optically pumped by n-UV chip and blue-chip thanks to its excitation-dependable property. Moreover, it also shows promising performance as X-ray scintillator with low detection limit of 60.79 nGyair S-1 , steady-state light yield ≈54% of commerical scintillaotr LuAG:Ce, high resolution of 13.5 lp mm-1 for X-ray imaging. This work presents a new structural design to fabricate 0D hybrids with multicolor emissions.