Dual-Functional Defect Passivation in Dion-Jacobson Perovskite for Low-Dose X-ray Detection and Imaging

High-performance, low-dose X-ray imaging is crucial for medical diagnostics, security screening, and industrial inspection. Perovskite materials have received significant attention in the field of X-ray imaging in recent years. However, defects at grain boundaries and interfaces can lead to non-radiative recombination losses, which degrade the performance and stability of the devices. Herein, we develop an X-ray detector based on quasi-two-dimensional Dion-Jacobson (DJ) perovskite and incorporated 3-methylamino-tetrahydrofuran hydrochloride (3-MTHFA-HCl) medical intermediate as a dual-functional agent to passivate the defects in the device. This compound effectively passivates both Lewis acid defects and iodine vacancies within the perovskite lattice due to it multifunctional molecular structure with both electron-rich and electron-poor functional groups. As a result, optimized detector achieves a remarkable sensitivity of ~21,000 μC Gyair−1 cm−2 and an ultralow detection limit of 6.75 nGyair s−1 even at a low bias of 40 V. The flat-panel X-ray imager (FPXI) developed by integrating perovskites with thin-film transistor (TFT) backplane demonstrates a spatial resolution of 3.4 lp mm−1, delivering high-contrast imaging at low X-ray dose of ~10 μGyair. The capability to capture intricate internal structures of plants and electronic devices underscores the significant application potential of our FPXI in advanced imaging technologies.