大型溶液成長無機ペロブスカイト単結晶を用いた超低検出限界ポータブル線量計

Inorganic perovskite CsPbCl₃ single crystals (SCs) grown via low-cost solution methods typically achieve sizes smaller than 1 mm, primarily due to the low solubility of the raw materials in solvents. This limitation significantly constrains their viability for X-ray detection applications. To address this challenge, an effective strategy is developed that not only increased the solubility of raw materials by 28 times but also significantly improved the crystallization matching between different components. This advance enabled the successful growth of high-quality CsPbCl₃-based SCs reaching 13 mm in size using a low-temperature solution process. The solution-grown SCs exhibit low trap density (∼10⁸ cm^-3), large resistivity (2.35 ×10⁹ Ω cm), high µτ product (1.02 ×10^-3 cm² V^-1), and superior uniformity. Therefore, X-ray detectors fabricated on these SCs achieved a record-high sensitivity of 2.19 ×10⁵ µC Gy^-1 cm^-2, a short response time of 307 µs, low noise current, and stable response output. Owing to these superior figures of merit, a prototype portable dosimeter assembled by the SC detector exhibited an extremely low detectable radiation of 0.07 nSv s^-1. Furthermore, the high-definition X-ray imaging of the SC detector is also demonstrated. This work provides an effective approach for the low-cost manufacturing of high-performance X-ray detection systems.