Perovskite materials, especially metal halide perovskites have attracted interest as a solar cell materials since the discovery of their semiconducting behavior. They can also be used as radiation detectors and offer advantages such as the ability to be fabricated over large areas and a lower cost. Another advantage is that heavy elements like lead within them act as absorption materials for photons, making them attractive for use in X-ray and γ-ray detectors. In this article, we review the characteristics of perovskite semiconductor and recent developments in radiation detectors utilizing them. We also introduce the current status of our detector development.

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Demands for analysis of new materials, for instance, interface structure of light element materials, voids in resins, and structure of carbon-based composite materials are increasing, and new methods and inspection equipment such as microfocus X-ray CT and X-ray phase imaging are being developed. Improving the performance of these equipment, it is important to develop an X-ray detector with sufficient sensitivity and resolution. We focused on halide perovskite materials, which have been developed significantly as solar cell materials. We aimed to develop an X-ray detector with the sensitivity of a CdTe (cadmium telluride) radiation detector and the spatial resolution of a CCD using Methylammonium Lead Iodide (MAPbI₃), forming an X-ray photoelectric conversion MAPbI₃ film on a charge readout substrate directly. We dropped a solution in which MAPbI₃ microcrystals were dispersed onto a substrate and heated it to create a uniform polycrystalline 1mm thick film, and evaluated its X-ray detection characteristics. Furthermore, to improve the performance of the detector, we examined the charge injection blocking layer and the quality of the perovskite film by using additives. In this paper, we will discuss the development of these elemental technologies to realize the high-sensitivity, high-resolution perovskite radiation detector.

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We evaluated the crystal quality and carrier transport properties of TlBr semiconductor detectors. We compared the results of the crystal quality evaluated by neutron diffraction and the carrier transport properties evaluated by the time-of-flight method using pulsed-laser-induced carriers.

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This paper presents advancements in Cadmium Zinc Telluride (CdZnTe) detector technology utilizing the Drift Strip Method (DSM). The DSM encapsulates a specific strip electrode design together with associated pulse shape analysis procedures, enabling high-resolution spectroscopy and 3D position sensitivity achievable from CdZnTe detectors. We demonstrate how this technology has evolved from early proof-of-concept studies to sophisticated 3D position-sensitive detectors with sub-millimeter spatial resolution and excellent spectral performance. The paper highlights key developments in electrode geometry, signal processing techniques, and applications in fields ranging from astrophysics to medical imaging. Performance evaluations of large-area 3D CdZnTe drift strip detectors show energy resolutions approaching the Fano-limited values, with demonstrated capabilities for particle discrimination and Compton camera applications.

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