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The demand for low-cost, easy to produce, flexible, and lightweight ionizing radiation detectors has grown extensively recently. Metal halide perovskites can meet all the demands of innovative radiation detectors and have rapidly outperformed the sensitivity of standard detectors.[1]
Here, we present perovskite-based composites fabricated by simple, low-cost, air-processed, dry mechanochemical synthesis of CsPbBr3 in a poly(butyl methacrylate) (PBMA) matrix.[2,3] The technique allows reproducible and easily scalable fabrication of thick perovskite pellets, by pressing the precursors into free-standing thick disks of thickness up to several hundreds of micrometres. Subsequently, the disks can be laminated onto a substrate with patterned electrodes to make photoconductors suitable as detectors of ionizing radiation. By tuning the polymer content, it is possible to achieve an extremely stable direct X-ray detection with good sensitivity. The devices are stable in air, bias and they are radiation hard, making them suitable for ionizing radiation detection in real-life applications. The perovskite-polymer composites are further investigated in vertical electrodes geometry to improve the charge collection efficiency. The vertical device configuration allows obtain a sensitity which is more than douled compared to a co-planar electrode geometry with the same active layer thickness (100 µm) and at the same applied electric field. The sensitivity can be further improved increasing the active layer thickness up to 500 µm, which is achievable thanks to the versatility of the dry-pressing fabrication technique. When laminated onto PET plastic substrate, the devices show outstanding flexibility properties reaching a bending radius of 1 mm with unaltered radiation response for a 100 µm thick device. Furthermore, the devices were tested also under a 5 MeV proton beam, demonstrating to make suitable flexible proton detectors.
To conclude, the synthesis of polymer micro-encapsulated perovskite pellets through simple, scalable, dry processes is promising for the development of flexible, stable, and highly sensitive ionizing radiation detectors.
[1] Dudipla K.R. et al, Adv. Mater. 2023, 2304523
[2] B. Huisman et al, Adv. Funct. Mater. 2024, 2308844
[3] C. Bordoni et al, Adv. Opt. Mater. 2026 e00004.