Ion Diffusion-Induced Multi-Interface Reconstruction for High-Resolution Perovskite X-Ray Flat-Panel Detectors

A critical challenge with state-of-the-art perovskite x-ray flat-panel detectors (FPDs) is their limited spatial resolution, primarily due to the presence of multiple poorly integrated interfaces. In this study, we report high-resolution perovskite FPDs that achieve a record modulation transfer function (MTF) among polycrystalline perovskite direct-conversion x-ray FPDs of 6.2 line pairs per millimetre (lp mm^-1) with a large imaging area of 8.5 × 8.5 cm² through an interface reconstruction strategy specifically tailored for perovskites. We reveal that Fick's law-guided ion diffusion across hundreds of microns-thick perovskites contributes to a reconstructed x-ray sensing layer with highly integrated interfaces and a gradient energy band alignment. As such, we have realized an ultrasensitive x-ray detection with a leading sensitivity-to-dark current ratio (2.61 × 10¹¹ µC Gy_air ^-1 A^-1) and outstanding stability under ambient conditions over 5760 h. The prototype perovskite FPDs exhibit a detective quantum efficiency (76.9%) and enable high-resolution x-ray imaging at a low dosage (0.98 µGy_air), substantially lower than previous polycrystalline perovskite FPDs. Our multi-interface reconstruction strategy successfully addresses long-standing issues in perovskite FPDs, advancing their progress from laboratory prototypes to commercial applications in digital radiography and industrial inspection.