High-spatial-resolution, melt-cast perovskite X-ray imager

The key asset of X-ray medical imaging lies in detecting fine features, governed by detector spatial resolution and high detection efficiency. Metal halide perovskites are emerging semiconductors with potential to exceed state-of-the-art direct-conversion and scintillation materials, featuring ∼10 lp mm⁻¹ spatial resolution. Yet, integrating high-quality perovskite layers with readout arrays remains challenging. Here, we demonstrate fabrication of thick, large-grain polycrystalline CsPbBr₃ films by melting directly on pixelated glass interposers. The obtained array detectors show a remarkable 20 lp mm⁻¹ intrinsic spatial resolution at MTF20, detection efficiency of 75.4%, and a low noise-equivalent dose of ∼46 photons for 22 keV X-rays under low reverse bias. These features enable unprecedented charge-integrating performance with 20% detective quantum efficiency at the Nyquist frequency. Single-pixel devices show single-photon counting of γ-radiation, resolving the 60 keV ²⁴¹Am peak. Melt-grown CsPbBr₃ films thus uniquely combine detection efficiency, scalability, and cost-effectiveness for next-generation low-dose, high-resolution X-ray imaging.