Ultrasensitive 3D Aerosol-Jet-Printed Perovskite X-ray Photodetector.

X-ray photon detection is important for a wide range of applications. The highest demand, however, comes from medical imaging, which requires cost-effective, high-resolution detectors operating at low-photon flux, therefore stimulating the search for novel materials and new approaches. Recently, hybrid halide perovskite CH ₃ NH ₃ PbI ₃ (MAPbI ₃ ) has attracted considerable attention due to its advantageous optoelectronic properties and low fabrication costs. The presence of heavy atoms, providing a high scattering cross-section for photons, makes this material a perfect candidate for X-ray detection. Despite the already-successful demonstrations of efficiency in detection, its integration into standard microelectronics fabrication processes is still pending. Here, we demonstrate a promising method for building X-ray detector units by 3D aerosol jet printing with a record sensitivity of 2.2 × 10 ⁸ μC Gy _air ^-1 cm ^-2 when detecting 8 keV photons at dose rates below 1 μGy/s (detection limit 0.12 μGy/s), a 4-fold improvement on the best-in-class devices. An introduction of MAPbI ₃ -based detection into medical imaging would significantly reduce health hazards related to the strongly ionizing X-rays' photons.