Heterointerface Design of Perovskite Single Crystals for High‐Performance X‐Ray Imaging

Metal halide perovskite single crystals (MHP-SCs) are known for their facile fabrication into large sizes using inexpensive solution methods. Owing to their combination of large mobility-lifetime products and strong X-ray absorption, they are considered promising materials for efficient X-ray detection. However, they suffer from large dark currents and severe ion migration, which limit their sensitivity and stability in critical X-ray detection applications. Herein, a heterointerface design is proposed to reduce both the dark current and ion migration by forming a heterojunction. In addition, the carrier transport performance is significantly improved using heterointerface engineering by designing a gradient band structure in the SCs. The SC heterojunction detectors exhibit a high sensitivity of 3.98 × 10