Strong Hydrogen Bond Interaction Induced Dimensional Evolution in Aromatic Diammonium-Based Perovskite/Perovskitoid for Achieving High-Performance X-ray Detection

Abstract 2D perovskite single crystals (SCs) based on various aromatic diammonium cations have demonstrated significant potential in high-performance X-ray detection. Nevertheless, the relationship between the structure of aromatic diammonium cations and perovskite dimension remains elusive. Herein, four aromatic diamine ligands of 4,4′-bipyridine (BPD), 4,4′-azopyridine (APD), 4,4′-vinylenedipyridine (VPD), and 4,4′-ethylenedipyridine (EPD) are selected to synthesize the target perovskites. A dimensional evolution from non-perovskite (EPDI2)•I2, 1D perovskitoids (BPD)PbI4 and (VPD)Pb2I6 to 2D perovskite (APD)PbI4 is observed. The strong hydrogen bond interactions contribute to edge-to-face arrangement of APD2+ cations instead of face-to-face packing of BPD2+, VPD2+ and EPD2+ cations, efficiently weakening the intermolecular cation–π interaction. Additionally, 2D (APD)PbI4 SCs feature enhanced crystallization quality, lattice rigidity, and ion migration activation energy owing to the strong hydrogen bond interactions. Consequently, (APD)PbI4 SC detectors exhibit high sensitivity (8375 μC Gy−1 cm−2), excellent operating stability, and high-quality X-ray imaging at 1.33 μGy s−1.