Novel Self‐Powered Sensitive X‐Ray Detection Crystal Bi ₂ Mo _0.36 W _1.64 O ₉ with Effective Functional Motif Coupling in a Quasi‐2D Perovskite Structure

Abstract The demand for medical imaging with reduced patient dosage and higher resolution is growing, driving the need for advanced X‐ray detection technologies. This paper proposes a design paradigm for X‐ray detection semiconductors by coupling constituent motifs through crystal structure engineering. The study introduces a strongly anisotropic Aurivillius‐type quasi‐2D perovskite structure, combining [Bi ₂ O ₂ ] ²⁺ groups with stereochemically active lone pair electrons (SCALPEs) and [W/Mo ₂ O ₇ ] ²⁻ anionic groups, enabling enhanced X‐ray Compton scattering and self‐powered capabilities through local electric field ordering. This results in the first self‐powered Bi‐based tungstate Bi ₂ Mo _0.36 W _1.64 O ₉ (BMWO) X‐ray detector, achieving a record self‐powered sensitivity of 381 µC Gy ⁻¹ cm ⁻² . Additionally, the study demonstrates the imaging capability of a Bi‐based perovskite X‐ray detector operating in self‐driven mode. The work highlights BMWO as a promising candidate for stable direct detection imaging and validates the material design strategy that leverages the large anisotropy of quasi‐2D structures for sensitive and self‐powered detection.