High-Performance X-ray Detection and Imaging Using ⟨110⟩-Oriented 2D (AABA)PbBr₃·H₂O Perovskite Single Crystals

Two-dimensional (2D) ⟨100⟩-oriented MHPs offer broad application prospects in X-ray detection due to extremely low detection limits and noise. Their multiquantum well structure limits interlayer carrier transport, significantly reducing X-ray sensitivity. High-quality, large-sized (AABA)PbBr₃·H₂O single crystals with ⟨110⟩ orientation were grown using an improved cooling crystallization method. The interconnected [PbX₆]^4- octahedra resulted in an inorganic layer spacing of 6.8615 Å. This small interlayer spacing enhances electron cloud overlap and improves interlayer transport. Ethyl side chains increase steric hindrance. A Pb-Br-Pb bond angle of 172.59° reduces octahedral tilting, weakening electron-phonon coupling and promoting charge transport. The (AABA)PbBr₃·H₂O X-ray detector exhibited excellent X-ray detection capabilities with sensitivity as high as 440 μC·Gy_air^-1·cm^-2 at 50 keV X-ray and detection limit as low as 20.85 nGy_air·s^-1, setting a leading benchmark for 2D MHPs. Undistorted X-ray imaging was achieved at low dose rates (30.83 μGy_air·s^-1) with the (AABA)PbBr₃·H₂O X-ray detector, and excellent stability was exhibited to meet requirements for dynamic digital imaging. The (AABA)PbBr₃·H₂O X-ray detector shows a high potential for medical diagnostics.