3D/1D Perovskite Heterojunction for High‐Performance Direct X‐ray Detector

Due to the strong X-ray attenuation coefficient, high carrier mobility-lifetime product, remarkable detection efficiency, and high-resolution imaging capability, metal halide perovskites have attracted increasing attention in the field of X-ray detection, known as promising candidates for next-generation high-performance radiation monitoring semiconductor materials. However, critical challenges, such as high dark current and pronounced ion migration, particularly in 3D perovskites, hinder their practical applications. Here, a unique 3D/1D perovskite heterojunction is presented as an effective strategy to address these limitations, where a distinctive, crisscross-structured 1D perovskite crystal with a planar and smooth surface is synthesized to form a robust interface with the 3D perovskite crystal. Benefiting from the synergistic effects of the heterostructure and 1D quantum wells, the resulting 3D/1D heterojunction exhibits a high ion migration activation energy, significantly suppressing ion migration and reducing the dark current. Consequently, the fabricated direct X-ray detector demonstrates exceptional operational and storage stability, achieving a high detection sensitivity of 1.03 × 10⁵ µC Gy_air ^-1 cm^-2 and a low detection limit of 4.9 nGy_air s^-1. Furthermore, X-ray imaging experiments confirm the superior imaging quality and spatial resolution of the 3D/1D perovskite heterojunction device, highlighting its potential for high-performance, stable, and reliable X-ray detection applications.