Structural Reconfiguration via Alternating Cation Intercalation of Chiral Hybrid Perovskites for Efficient Self-Driven X-ray Detection.

2D hybrid perovskites (HPs) have great potential for high-performance X-ray detection due to their strong radiation absorption and flexible structure. However, there remains a need to explore avenues for enhancing their detection capabilities. Optimizing the detection performance through modification of their structural properties presents a promising strategy. Herein, we explore the impact of modifying the organic spacer layer in two distinct 2D layered HPs, namely, Ruddlesden-Popper (-MPA)PbBr (, -MPA = methylphenethylammonium) and (-MPA)EAPbBr (EA = ethylammonium) () with alternating cation intercalation (ACI), on their X-ray detection performance. The insertion of EA into results in a flatter inorganic skeleton, narrower spacing, and higher density compared to . This structural modification effectively optimizes carrier transport and X-ray absorption in , enhancing the X-ray detection performance. Notably, exhibits a polar structure with intrinsic spontaneous polarization, contributing to a bulk photovoltaic of 0.4 V. This feature enables single-crystal detectors to achieve self-driven X-ray detection with a low detection limit of 82.5 nGy s under a 0 V bias. This work highlights the efficacy of the ACI strategy in structural modification and its significant effect on X-ray detection properties, providing insights for the design and optimization of new materials.