Thermally and Bias-Stable FAPbBr 3 Perovskite Single-Crystalline Radiation Detectors Enabled by Interpenetrating Titanium Mesh Electrode

Perovskite single crystals exhibit great potential for high-sensitivity radiation detection. However, single-crystal detectors suffer from intrinsic mechanical instability: weak van der Waals interactions and significant thermal expansion coefficient mismatches between perovskite and metal electrodes, which shall collectively induce device delamination and failure─especially under temperature fluctuations. Here, we address this challenge by resorting to a nonconventional device architecture: we directly grow perovskite single crystals on porous titanium meshes (serving as electrodes) in solution, yielding a titanium-perovskite interpenetrating network structure. Unlike conventional planar electrodes that rely on van der Waals interaction with perovskite, this architecture leverages the intrinsic cohesive energy of both perovskite and titanium with additional three-dimensional stress distribution. The resulting FAPbBr 3 single-crystalline devices achieve unprecedented stability against thermal shock (−20 to 200 °C) and high voltages (1330 V/cm), while maintaining excellent mechanical integrity and detection performances. This nonplanar device structure, coupled with its unique fabrication process, provides an alternative strategy for developing highly stable and sensitive perovskite radiation detectors.