X-rays are widely used in probing inside information nondestructively, enabling broad applications in the medical radiography and electronic industries. X-ray imaging based on emerging lead halide perovskite scintillators has received extensive attention recently. However, the strong self-absorption, relatively low light yield and lead toxicity of these perovskites restrict their practical applications. Here, we report a series of nontoxic double-perovskite scintillators of Cs₂Ag_0.6Na_0.4In_1-yBi_yCl₆. By controlling the content of the heavy atom Bi³⁺, the X-ray absorption coefficient, radiative emission efficiency, light yield and light decay were manipulated to maximise the scintillator performance. A light yield of up to 39,000 ± 7000 photons/MeV for Cs₂Ag_0.6Na_0.4In_0.85Bi_0.15Cl₆ was obtained, which is much higher than that for the previously reported lead halide perovskite colloidal CsPbBr₃ (21,000 photons/MeV). The large Stokes shift between the radioluminescence (RL) and absorption spectra benefiting from self-trapped excitons (STEs) led to a negligible self-absorption effect. Given the high light output and fast light decay of this scintillator, static X-ray imaging was attained under an extremely low dose of ∼1 μGy_air, and dynamic X-ray imaging of finger bending without a ghosting effect was demonstrated under a low-dose rate of 47.2 μGy_air s⁻¹. After thermal treatment at 85 °C for 50 h followed by X-ray irradiation for 50 h in ambient air, the scintillator performance in terms of the RL intensity and X-ray image quality remained almost unchanged. Our results shed light on exploring highly competitive scintillators beyond the scope of lead halide perovskites, not only for avoiding toxicity but also for better performance.

X射线广泛用于无损探测内部信息，在医学放射成像和电子行业中得到广泛应用。基于新兴卤化铅钙钛矿闪烁体的X射线成像最近受到广泛关注。然而，这些钙钛矿的强自吸收、相对较低的光产额和铅毒性限制了它们的实际应用。在这里，我们报道了一系列无毒的Cs ₂ Ag _0.6 Na _0.4 In _1-y Bi _y Cl ₆双钙钛矿闪烁体。通过控制重原子Bi ³⁺的含量，可以控制X射线吸收系数、辐射发射效率、光产额和光衰，以最大化闪烁体的性能。 Cs ₂ Ag _0.6 Na _0.4 In _0.85 Bi _0.15 Cl ₆的光产额高达 39,000 ± 7000 光子/MeV，远高于之前报道的卤化铅钙钛矿胶体 CsPbBr ₃ (21,000 光子/MeV) 。得益于自陷激子 (STE)，辐射发光 (RL) 和吸收光谱之间的大斯托克斯位移导致自吸收效应可以忽略不计。鉴于该闪烁体的高光输出和快速光衰，在~ 1μGy的极低剂量_空气下实现了静态X射线成像，并且在低剂量下演示了手指弯曲的动态X射线成像，没有重影效应。 47.2μGy_空气s ^-1的剂量率。 在 85 °C 热处理 50 小时，然后在环境空气中 X 射线照射 50 小时后，闪烁体在 RL 强度和 X 射线图像质量方面的性能几乎保持不变。我们的研究结果为探索超越卤化铅钙钛矿范围的高度竞争性闪烁体提供了线索，不仅可以避免毒性，而且可以提高性能。