Multi‐Site Engineering Enables High‐Performance and Stable Perovskite X‐Ray Detectors

ABSTRACT Halide perovskite thick films have emerged as promising candidates for X‐ray detection and imaging. However, the residual strain arising from soft lattice, lattice mismatch, and weak interfacial bonding causes cracks and delamination, hindering the integration of perovskite film with thin film transistor (TFT). Here, a multifunctional natural molecule (digallic acid, DA) is introduced into the ultrasonic spraying perovskite film to achieve efficient and stable fully air‐processed X‐ray detectors. Results demonstrate that DA's abundant functional groups not only enhance adhesion between perovskite films and substrates to improve the integrability with TFT, but also effectively passivate defects. Furthermore, this approach modulates the perovskite's Fermi level, creating an interfacial barrier that significantly reduces dark current. Consequently, DA modification enables the device to obtain a high sensitivity of 3.1 × 10 5 µC Gy air −1 cm −2 and a low detection limit of 39.8 nGy air s −1 , simultaneously greatly enhances the tolerance to irradiation, remaining stable after 140 Gy air X‐ray irradiation. The flat‐panel detector, integrating DA‐modified perovskite film with TFT backplane, successfully achieved rapid X‐ray imaging under low dose rate (92 ms/frame, 27.2 µGy air s −1 , tolal dose of 2.5 µGy air ). This work highlights DA's potential as a versatile molecular tool for developing low‐dose, high‐performance X‐ray imaging systems.