Molecular Design of Layered Hybrid Silver Bismuth Bromine Single Crystal for Ultra-Stable X-Ray Detection with Record Sensitivity.

Nowadays, weak interlayer coupling and unclear mechanism in layered hybrid silver bismuth bromine (LH-AgBiBr) is the main reason for limiting its further enhanced X-ray detection sensitivity and stability. Herein, the design rules for LH-AgBiBr and its influence on X-ray detection performance were reported for the first time. Although shortening amine size could enhance interlayer coupling, its detection performance is severely hampered by its easier defect formation caused by enlarged micro strain. In contrast, an appropriate divalent amine design endowed the material with improved interlayer coupling and released micro strain, which benefits crystal stability and mechanical hardness. Another contribution is to increase material density and dielectric constant, thus enhancing X-ray absorption and carrier transport. Consequently, the optimized parallel device based on BDA 2 AgBiBr 8 achieved a record sensitivity of 2638 μC Gy air -1 cm -2 and an ultra-low detection limit of 7.4 nGy air s -1 , outperforming other reported LH-AgBiBr X-ray detectors. Moreover, the unencapsulated device displays remarkable anti-moisture, anti-thermal (> 150˚C), and anti-radiation (> 1000 Gy air ) endurance. Eventually, high-resolution hard X-ray imaging was demonstrated by linear detector arrays under a benign dose rate (1.63 μGy air s -1 ) and low external bias (5 V). Hence, our findings provide guidelines for future materials design and device optimization. This article is protected by copyright. All rights reserved.