Revolutionizing X-ray Imaging: A Leap toward Ultra-Low-Dose Detection with a Cascade-Engineered Approach.

X-ray detection technology is essential in various fields, including medical imaging and security checks. However, exposure to large doses of X-rays poses considerable health risks. Therefore, it is crucial to reduce the radiation dosage without compromising detection efficiency. To address this concern, we propose an innovative cascade-engineered approach that uses two interconnected single-crystal devices to mitigate dark current and enhance the detection limit. Using laboratory-grown methylammonium lead bromide (MAPbBr) perovskite single crystals, we engineered devices that significantly reduced detection thresholds and improved signal-to-noise ratios (SNRs). The detection threshold dropped from 590 nGy·s with the conventional method to 100 nGy·s using the cascade approach, surpassing the most recent record of 500 nGy·s achieved for MAPbBr devices under nearly identical conditions. The dark current was halved compared to that of conventional devices, and spatial resolution improved from 5.6 to 8.5 lp·mm. Imaging trials confirmed improved resolution and effectiveness at low doses, highlighting the approach's potential for medical diagnostics that prioritizes reducing radiation exposure without compromising image quality. The groundbreaking nature of this approach is highlighted by its adaptability across diverse electrical environments and crystal types, as evident in CdTe crystals, indicating its potential for widespread utilization in low-dose leakage monitoring and commercial X-ray devices.