High-Performance and Self-Powered X-Ray Detectors Made of Smooth Perovskite Microcrystalline Films with 100 mu m 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 mu m, which endows the microcrystalline films with comparable carrier mobility-lifetime (mu tau) product as single crystals. As a result, self-powered X-ray detectors with impressive sensitivity of 6.1x10(4) mu C 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 mu s), this work may contribute to the development of perovskite-based low-dose X-ray imaging.