Multi‐axial Self‐driven X‐ray Detection by a Two‐dimensional Biaxial Hybrid Organic‐Inorganic Perovskite Ferroelectric

Metal halide perovskite ferroelectrics combining spontaneous polarization and excellent semiconducting properties is an ideal platform for enabling self-driven X-ray detection. However, achievements to date have been only based on uniaxiality, which increases the complexity of device fabrication. Multi-axial ferroelectric materials have multiple equivalent polarization directions, making them potentially amenable to multi-axial self-driven X-ray detection, but the report on these types of materials is still a huge blank. Herein, a high-quality (BA)