Highly sensitive X-ray detection is crucial in, for example, medical imaging and secure inspection. Halide perovskite X-ray detectors are promising candidates for detecting highly energetic radiation. In this report, we describe vacuum-deposited Cs-based perovskite X-ray detectors possessing a p–i–n architecture. Because of the built-in potential of the p–i–n structure, these perovskite X-ray detectors were capable of efficient charge collection and displayed an exceptionally high X-ray sensitivity (1.2 C Gyair –1 cm–3) under self-powered, zero-bias conditions. We ascribe the outstanding X-ray sensitivity of the vacuum-deposited CsPbI2Br devices to their prominent charge carrier mobility. Moreover, these devices functioned with a lowest detection limit of 25.69 nGyair s–1 and possessed excellent stability after exposure to over 3000 times the total dose of a chest X-ray image. For comparison, we also prepared traditional spin-coated CH3NH3-based perovskite devices having a similar device architecture. Their volume sensitivity was only one-fifth of that of the vacuum-deposited CsPbI2Br devices. Thus, all-vacuum deposition appears to be a new strategy for developing perovskite X-ray detectors; with a high practical deposition rate, a balance can be reached between the thickness of the absorbing layer and the fabrication time.

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In this study, an inspection system for indium tin oxide (ITO) circuits has been developed. In the developed system, a polymer dispersed liquid crystal (PDLC)/ITO film is used as a sensing device to locate faulty shut/open circuits. The examined object and the PDLC/ITO film are both linked to an external power source to form an electric field. With the power on, the crystals line up, re-orientate themselves and the film covering the conducting area turns clear while the liquid crystals covering the non-conducting area are randomly scattered and diffuse light in all directions. The voltage range of the power source required to change the state of the PDLC film was estimated theoretically. Simulations were conducted to study the effects of the external power on the performance of the developed system. The results were then verified experimentally. It was shown that the developed system is a feasible system for ITO circuit inspection.

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