The effective detection of X-ray radiation with low threshold is essential to many medical and industrial applications. Three-dimensional (3D) organolead trihalide and double perovskites have been shown to be suitable for direct X-ray detection. However, the sensitivity and stability of 3D perovskite X-ray detectors are limited by ion motion, and there remains a demand to develop green and stable X-ray detectors with high sensitivity and low detection limit. The emerging low-dimensional perovskites have shown promising optoelectronic properties, featuring good intrinsic stability and reduced ion migration. Inspired by this, we show that our 2D layered perovskite-like (NH₄)₃Bi₂I₉ device provides unique anisotropic X-ray detecting performance with different crystal directions, effective suppression of ion migration and a low detection limit of 55 nGy_air s⁻¹. These results will motivate new strategies to achieve a high-performance X-ray detector by utilizing 2D layered perovskite or perovskite-like materials, without requiring toxic elements.

具有低阈值的X射线辐射的有效检测对于许多医疗和工业应用都是必不可少的。三维（3D）有机三卤化铅和双钙钛矿已被证明适用于直接X射线检测。然而，3D钙钛矿X射线检测器的灵敏度和稳定性受到离子运动的限制，并且仍然需要开发具有高灵敏度和低检测限的绿色且稳定的X射线检测器。新兴的低维钙钛矿显示出令人鼓舞的光电性能，具有良好的固有稳定性和减少的离子迁移。受此启发，我们表明我们的二维层状钙钛矿状（NH ₄）₃ Bi ₂ I ₉该器件提供了独特的各向异性X射线检测性能，具有不同的晶体方向，有效的离子迁移抑制和低的55 nGy_空气 s ^-1检测极限。这些结果将激发利用二维层状钙钛矿或类钙钛矿材料而不需要有毒元素的高性能X射线探测器的新战略。