Two‐Dimensional Perovskite Single Crystals for High‐Performance X‐ray Imaging and Exploring MeV X‐ray Detection

Scintillation semiconductors play increasingly important medical diagnosis and industrial inspection roles. Recently, two‐dimensional (2D) perovskites have been shown to be promising materials for medical X‐ray imaging, but they are mostly used in low‐energy (≤130 keV) regions. Direct detection of MeV X‐rays, which ensure thorough penetration of the thick shell walls of containers, trucks, and aircraft, is also highly desired in practical industrial applications. Unfortunately, scintillation semiconductors for high‐energy X‐ray detection are currently scarce. Here, This paper reports a 2D (C 4 H 9 NH 3 ) 2 PbBr 4 single crystal with outstanding sensitivity and stability toward X‐ray radiation that provides an ultra‐wide detectable X‐ray range of between 8.20 nGy air s −1 (50 keV) and 15.24 mGy air s −1 (9 MeV). The (C 4 H 9 NH 3 ) 2 PbBr 4 single‐crystal detector with a vertical structure is used for high‐performance X‐ray imaging, delivering a good spatial resolution of 4.3 lp mm −1 in a plane‐scan imaging system. Low ionic migration in the 2D perovskite enables the vertical device to be operated with hundreds of keV to MeV X‐ray radiation at high bias voltages, leading to a sensitivity of 46.90 μC Gy air −1 cm −2 (−1.16 V μm −1 ) with 9 MeV X‐ray radiation, demonstrating that 2D perovskites have enormous potential for high‐energy industrial applications.