Constructing reverse electric field by buried interfacial heterojunction engineering enables high-performance perovskite X-ray detectors

Large-area halide perovskite thick films offer significant potential for next-generation X-ray detectors. However, bias-induced ion migration at buried interfaces significantly degrades device performance. Here, we introduce an innovative buried interface engineering strategy by incorporating a low-polarity solution (ethyl acetate)-processable 1D perovskite (PBL 4 PbI 6 , PBL = pregabalin) as bottom contact layer, which simultaneously addresses three critical issues: (1) low-polarity ethyl acetate eliminates solvent residue, improving device repeatability and stability; (2) low lattice mismatch (≈1.3%) of underlying 1D layer enables high-quality crystalline growth of top 3D layer; (3) a built-in reverse electric field at 1D/3D heterostructure, enables efficient carrier extraction, while suppressing excessive field-induced ion migration. As a result, ion migration activation energy increases from 149 to 182 meV. The optimized detectors achieve a high sensitivity of 76,553 μC Gy air −1 cm −2 and a low detection limit of 9.5 nGy air s −1 , outperforming most reported perovskite thick-film X-ray detectors based on interface engineering.