Photon-counting radiation detectors based on metal-halide perovskites and derivatives

Photon-counting detectors (PCDs), capable of measuring both radiation dose and energy, are increasingly important across a wide range of applications involving ionizing radiation, including medical imaging, radioisotope detection, and nuclear security. Lead-halide perovskites (LHPs) have demonstrated exceptional optoelectronic properties, which have enabled their rise in performance in photovoltaics and are now contributing to their rapid progress in PCDs. Herein, we discuss the principles of direct and indirect photon-counting detection, emphasizing the advantages of PCDs over conventional energy-integrating detectors and the limitations of current commercial technologies. We highlight key materials' attributes that make LHPs attractive for radiation detection and discuss recent progress in perovskite-based direct detectors and scintillator-based PCDs. Additionally, we discuss the progress and future potential of Pb-free perovskite derivatives and the related materials for PCDs. Finally, we outline future research priorities, potential commercialization pathways, and the challenges that must be addressed to realize practical perovskite-based PCD technologies.