Multiaxial Aromatic‐Based Photoferroelectric Induced by Synergistic Intermolecular Interactions for Multidirectional Self‐Powered X‐Ray Detection
Lijun Xu, Zhenyue Wu, Ye Huang, Qianwen Guan, Hang Li, Chengshu Zhang, Chengmin Ji, Junhua Luo
Abstract
Abstract Photoferroelectrics coupling spontaneous polarization and remarkable semiconductor attributes have emerged as promising candidates for self‐powered X‐ray detection. However, the effective construction of multiaxial aromatic photoferroelectrics for stable multidirectional self‐powered X‐ray detection remains a great blank. Herein, we report for the first time the successful design of a multiaxial aromatic‐based photoferroelectric, (4Br2FBZ) 2 PbBr 4 (4Br2FBZ = 4‐bromo‐2‐fluorobenzylammonium), through synergistic noncovalent interactions of hydrogen bonding and fluorine‐π, which achieves a stable multidirectional self‐powered X‐ray detection. Notably, the aromatic cations rotate driven by synergistic molecular interactions to form a T‐shaped stacking architecture, resembling interlocking puzzle pieces. This oriented arrangement generates electric dipoles, inducing four equivalent polarization directions, which endow (4Br2FBZ) 2 PbBr 4 with a large spontaneous polarization of 4.48 µC cm −2 and a high Curie temperature of 408 K. The combination of its biaxial nature and strong intermolecular interaction network, self‐powered X‐ray detectors assembled along two polar axes demonstrate high sensitivities (181.7 and 175.3 µC Gy −1 cm −2 ), and exceptional detection stability. Strikingly, the polycrystalline ferroelectric film also exhibits excellent self‐powered X‐ray detection behavior due to its biaxial ferroelectricity, indicating the potential for next‐generation flexible and thin‐film integrated devices.