Direct Fast‐Neutron Detection by 2D Perovskite Semiconductor

Abstract Fast‐neutrons play a critical role in a range of applications, including medical imaging, therapy, and nondestructive inspection. However, direct detecting fast‐neutrons by semiconductors has proven to be challenging due to their weak interaction with most matter and the requirement of high carrier mobility‐lifetime (µτ) product for efficient charge collection. Herein, a novel approach is presented to direct fast‐neutron detection using 2D Dion–Jacobson perovskite semiconductor BDAPbBr₄. This material features a high fast‐neutron caption cross‐section, good electrical stability, high resistivity, and, most importantly, a record‐highµτproduct of 3.3 × 10⁻⁴cm²V⁻¹, outperforming most reported fast‐neutron detection semiconductors. As a result, BDAPbBr₄detector exhibited good response to fast‐neutrons, not only achieving fast‐neutron energy spectra in counting mode, but also obtaining linear and fast response in integration mode. This work provides a paradigm‐shifting strategy for designing materials that efficiently detect fast‐neutrons and paves the way toward exciting applications in fast‐neutron imaging and therapy.