High-sensitive and fast MXene/silicon photodetector forsingle-pixel X-ray imaging

The demand for high-performance X-ray detectors leads to material innovationfor efficient photoelectric conversion and carrier transfer. However, currentX-ray detectors are often susceptible to chemical and irradiation instability,complex fabrication processes, hazardous components, and difficult compatibility.Here, we investigate a two-dimensional (2D) material with a relativelylow atomic number, Ti_(3)C_(2)T_(x) MXenes, and single crystal silicon for X-ray detectionand single-pixel imaging (SPI). We fabricate a Ti_(3)C_(2)T_(x) MXene/Si X-raydetector demonstrating remarkable optoelectronic performance. This detectorexhibits a sensitivity of 1.2 × 10^(7) μC Gyair^(-1) cm^(-2), a fast response speed with arise time of 31 μs, and an incredibly low detection limit of 2.85 nGyair s^(-1).These superior performances are attributed to the unique charge couplingbehavior under X-ray irradiation via intrinsic polaron formation. The deviceremains stable even after 50 continuous hours of high-dose X-ray irradiation.Our device fabrication process is compatible with silicon-based semiconductortechnology. Our work suggests new directions for eco-friendly X-ray detectorsand low-radiation imaging system.