上海科技大学知识管理系统

Metal halide perovskites have emerged as excellent direct X-ray detection materials owing to their large mobility-lifetime product, strong radiation absorption, and low-cost preparation. However, it is still a challenge to achieve stable X-ray detection due to the limitations associated with severe ion migration under high voltage bias. Herein, based on a bromine substitution strategy to suppress ion migration, a 2D alternating cations intercalation-type (ACI) perovskite, (R-MPA)(BrEA)PbBr4 (1, R-MPA = methylphenethylamm-onium; BrEA = 2-bromoethylamine) is reported to achieve X-ray detection. Specifically, introducing Br atom forms additional intermolecular interactions (i.e., Br···π) and enhances hydrogen bonding interactions, greatly improving the structure stability. Based on this enhanced interaction, 1 presents a higher activation energy of ion migration (1.05 eV) than that of (R-MPA)EAPbBr4 resulting in a lower dark current drift of 9.17 ×10- 8 nA cm- 1 s -1 V-1 , revealing that suppression of ion migration. Consequently, the 1-based detector shows a high sensitivity of 2653.7 μC Gy-1 cm-2 and, most importantly, outstanding operational and environmental stability, maintaining ≈91% of its initial sensitivity at 50 V bias after 90 days in the air. This work demonstrates an efficient strategy for introducing halogen interactions via ACI to suppress ion migration for stable X-ray detection.