Novel Self-Powered Sensitive X-Ray Detection Crystal Bi₂Mo_0.36W_1.64O₉ with Effective Functional Motif Coupling in a Quasi-2D Perovskite Structure

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 [Bi₂O₂]²⁺ groups with stereochemically active lone pair electrons (SCALPEs) and [W/Mo₂O₇]^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 Bi₂Mo_0.36W_1.64O₉ (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.