Perovskite Lattice Contraction Enhanced Charge Carrier Transport for Highly‐Sensitive X‐Ray Detection

Low‐dimensional hybrid halide perovskites (LDHPs) have attracted intensive attention in X‐ray detectors. However, they are still limited by their poor charge transfer capacity between organic and inorganic layers. And, the impact of the soft lattice variability characteristics on device performance is still unclear. Here, this study constructs a novel N, N‐Dimethylaminomethylferrocene (MAFc)‐based one‐dimensional (1D) perovskite single crystal, (MAFcH)PbI 3 •DMF (DMF = N, N‐Dimethylformamide), in which the protonated MAFcH can not only act as counter cations, but also as carriers’ transfer media to promote charge carriers’ transport. Significantly, (MAFcH)PbI 3 •DMF single crystal can be transformed into (MAFcH)PbI 3 single crystal through the loss of DMF. Notably, by controlling lattice contraction through the heating method, the (MAFcH)PbI 3 •DMF single crystal (13.1%) in the fabricated (MAFcH)PbI 3 •DMF (13.1%)/(MAFcH)PbI 3 single crystal device can promote effective separation and extraction of X‐ray induced charge carriers. The fabricated (MAFcH)PbI 3 •DMF (13.1%)/(MAFcH)PbI 3 single crystal device exhibits an excellent response to hard X‐rays (120 kV), and yields a high sensitivity of 1.7 × 10 4 µC Gy air −1 cm −2 with the lowest detectable X‐ray dose rate of 120 nGy air s −1 . Moreover, the fabricated X‐ray detector shows excellent long‐term X‐ray operational stability with no attenuation observed after 6 months of exposure to air without encapsulation.