Face-/Edge-Shared 3D Perovskitoid Single Crystals with Suppressed Ion Migration for Stable X-Ray Detector

• 3D perovskitoid Pb2CuGly2X4 single crystals with face-/edge-shared inorganic skeleton and CuGly2 pillars achieve a high ion migration activation energy of 1.06 eV, effectively suppressing ion migration. • The Pb2CuGly2Cl4 SC X-ray detector exhibits extremely low dark current drift (1.20 × 10–9 nA mm−1 s−1 V−1) under high electric field and continuous X-ray irradiation, ensuring high operating stability. • A high sensitivity of 9,250 μC Gy−1 cm−2 is achieved, surpassing many existing perovskite X-ray detectors. • The Pb2CuGly2Cl4 nanocrystals are water-dispersible and can be blade-coated on TFT arrays, enabling X-ray imaging with a spatial resolution of 2.2 lp mm−1, demonstrating practical applicability.