Vertically Oriented Porous PET as Template to Integrated Metal Halide for High‐Performance Large‐Area and Ultra‐Flexible X‐Ray Detector

Abstract High‐performance X‐ray detectors have immense potential in medical and security inspections. However, the current X‐ray detectors are limited in flexible, high‐spatial‐resolution large‐scale detection, and integration for imaging. Here, nuclear track‐etched porous polyethylene terephthalate (PET) is developed as the template for preparing uniform, large‐area (≥10 5 cm 2 ), and flexible metal halide (MH)‐based X‐ray detectors. Adjustable high‐density vertically oriented porous PET with adjustable thickness can provide proper physical support for flexible thick absorption film, thus improving X‐ray absorption ability with excellent bending stability. Moreover, vertical channels can block the ion migration, lateral charge diffusion, and water/oxygen attacks, increasing activation energy for ionic transport, charge collection rate of electrodes, and environmental stability. Hence, the related detectors eventually obtain large sensitivity (6722 µC Gy air −1 cm −2 ), low detection limit (1.87 nGy air s −1 ), and high spatial resolution (5.17 lp mm −1 ) compared to the detectors without porous PET template. Meanwhile, the device shows no degradation after storage or working under various thermal attacks. MH‐filled‐PET is also monolithically integrated on the bottom circuit with different MHs and it is applied to single‐pixel mode and fast linear‐array imaging in a broad range of X‐rays photon energy (20 to 160 keV).