Halide Perovskite Single Crystals for X-ray Detection

High-energy X-ray and γ-ray detection underpins medical imaging, security screening, industrial nondestructive evaluation, and scientific instrumentation, creating strong demand for semiconductor absorbers that deliver high detection performance while remaining scalable and cost-effective. Metal halide perovskite single crystals (HPSCs) have emerged as a potentially disruptive, low-cost alternative: they can be grown from inexpensive precursors using energy-efficient, low-temperature solution processes, and they combine high effective atomic numbers with favorable mobility-lifetime products that can approach or exceed commercial benchmarks. Relative to polycrystalline films, the absence of grain boundaries, ultralow defect densities, and efficient charge transport in HPSCs enable improved optoelectronic response and enhanced operational stability in detector architectures. Despite rapid progress in headline device metrics, the field has often emphasized empirical optimization over mechanistic understanding, leaving key relationships between intrinsic crystal quality, defect formation and kinetics, and long-term stability insufficiently resolved. In parallel, inconsistent reporting of crystal quality and nonstandard performance protocols complicate cross-study comparisons and impede translation to useful applications. This Review provides an integrated framework that connects detector physics, materials science, crystal growth, and device engineering to rationalize reported advances and to guide future development.