High-performance and self-powered X-ray detectors made of smooth perovskite microcrystalline films with 100 µm grains

Perovskite single crystals and polycrystalline films have complementary merits and deficiencies in X-ray detection and imaging. Herein, we report preparation of dense and smooth perovskite microcrystalline films with both merits of single crystals and polycrystalline films through polycrystal-induced growth and hot-pressing treatment (HPT). Utilizing polycrystalline films as seeds, multi-inch-sized microcrystalline films can be in situ grown on diverse substrates with maximum grain size reaching 100 µm, which endows the microcrystalline films with comparable carrier mobility-lifetime (µτ) product as single crystals. As a result, self-powered X-ray detectors with impressive sensitivity of 6.1×10${}^4$ µC Gy${}_{air}$${}^{-1}$ cm${}^{-2}$ and low detection limit of 1.5 nGy${}_{air}$ s${}^{-1}$ are achieved, leading to high-contrast X-ray imaging at an ultra-low dose rate of 67 nGy${}_{air}$ s${}^{-1}$. Combining with the fast response speed (186 µs), this work may contribute to the development of perovskite-based low-dose X-ray imaging. (© 2023 Wiley‐VCH GmbH)