Mn²⁺ Doping in Organic Zn(II)-Based Halides toward Significantly Enhanced Optical Characteristics and Stabilities

Hybrid metal halide perovskites have emerged as outstanding new scintillators due to their entire spectrum range coverage, high photoluminescence quantum yield (PLQY), low self-absorption, and large Stokes shift. However, Zn(II)-based halides exhibiting excellent scintillator properties remain relatively scarce. Herein, we employed a Mn²⁺-doping strategy to optimize zero-dimensional (0D) Zn(II)-based halides and realized highly efficient luminescence and scintillation performance. Compared with the weak bluish emission (439 nm, PLQY ∼ 1%) of (BACQ)₂ZnCl₄, the Mn²⁺-doping strategy results in a green emission at 533 nm with a significantly enhanced PLQY of 38%. This green emission originates from the d-d transition of the Mn²⁺ ions. Furthermore, (BACQ)₂ZnCl₄·4.7%Mn²⁺ demonstrates more excellent structural and optical stability in an aqueous environment than pristine (BACQ)₂MnCl₄. As a scintillator, (BACQ)₂ZnCl₄·4.7%Mn²⁺ displays excellent scintillation properties with a light yield of 17541 photons MeV^-1, a detection limit of 122.5 nGyair s^-1, a short afterglow of 1.45 ms, and robust radiation stability. These properties enable high-resolution X-ray imaging with a spatial resolution of 11.3 lp/mm. The superior scintillation performances present the feasibility of the metal doping strategy and promote the development of stable Zn(II)-based halides.