Hydrochloric Acid-Assisted Layered Perovskite CsMnCl3 2H2O Single Crystals for Sensitive and Stable X-ray Detection with Anisotropic Response

Low-dimensional lead-free perovskite single crystals (SCs) have exhibited great potential in high-energy ionizing radiation detections owing to their outstanding sensitivity and charge transport properties. However, the preparation of chlorine-based SCs is more challenging due to their low solubility in organic solvents and acidic solutions. In this work, we report a universal growth strategy of hydrochloric acid-assisted temperature lowering for low-dimensional layered perovskite CsMnCl3·2H2O SCs. Compared with SCs prepared by solution evaporation crystallization, centimeter-sized SCs were achieved with ultrahigh crystal quality, showing a very small full width at half-maximum of 0.02° at the plane (002). Our layered perovskite CsMnCl3 2H2O X-ray detector shows unique anisotropic X-ray detecting performance at parallel and perpendicular to the (002) crystal plane. An ultralow detection limit of 9.3 nGyair s–1 has been obtained, which is significantly lower than the 5.5 μGyair s–1 required for regular medical diagnostics. Furthermore, the device shows enhanced stability with a slight degradation of 8% after storage in air ambient for 6 months. Our work suggests a promising approach to fabricate high-quality SCs for sensitive and stable X-ray detection applications.