Triangular-Textured MoS2/FAPbI3 Heterojunction Membranes for Lightweight, Flexible, and Self-Powered Radiation Detection

Abstract Perovskite materials are promising for optoelectronic applications, but developing lightweight and flexible detectors remains challenging due to interfacial incompatibility and mechanical brittleness. Here, we demonstrate a lightweight, flexible, and self-powered radiation detector based on the triangular-textured MoS2/FAPbI3 heterojunction membranes. We show that the freestanding MoS2 single-crystal membrane functions as both mechanical support and epitaxial template for the deposition of FAPbI3 films. The formation of a type II heterojunction at the MoS2/FAPbI3 interface induces a built-in electric field and facilitates charge carrier collection, which enables an efficient X-ray detection device with a high sensitivity of 23 145 μC Gy–1 cm–2 and a low detection limit of 177 nGy s–1 operated under zero bias. More importantly, the MoS2/FAPbI3 device weighs just 1/200 of that of FTO-based device with the same 4-μm-thick perovskite layer and withstands 1000 repeated bending cycles at a bending strain of 0.1154% without obvious performance degradation.