Wang Zihan, Tie Shujie, Zhang Hui, Wan Changmao, Liang Zheng, Xu Huifen, Zheng Xiaojia, Zhang Wenhua, Aldakov Dmitry, Reiss Peter, Ye Jiajiu, Pan Xu
Institute of Solid-State Physics, Hefei Institutes of Physical Science, Chinese Academy of Science, Hefei 230031, China.
University of Science and Technology of China, Hefei 230026, China.
ACS Nano. 2023 Jul 25;17(14):13638-13647. doi: 10.1021/acsnano.3c02476. Epub 2023 Jul 5.
Halide perovskite materials possess excellent optoelectronic properties and have shown great potential for direct X-ray detection. Perovskite wafers are particularly attractive among various detection structures due to their scalability and ease of preparation, making them the most promising candidates for X-ray detection and array imaging applications. However, device instability and current drift caused by ionic migration are persistent challenges for perovskite detectors, especially in polycrystalline wafers with numerous grain boundaries. In this study, we examined the potential of one-dimensional (1D) δ-phase (yellow phase) formamidinium lead iodide (δ-FAPbI) as an X-ray detection material. This material possesses a suitable band gap of 2.43 eV, which makes it highly promising for X-ray detection and imaging using compact wafers. Moreover, we found that δ-FAPbI has low ionic migration, low Young's modulus, and excellent long-term stability, making it an ideal candidate for high-performance X-ray detection. Notably, the yellow phase perovskite derivative exhibits exceptional long-term atmospheric stability (RH of ≈70 ± 5%) over six months, as well as an extremely low dark current drift (3.43 × 10 pA cm s V), which is comparable to that of single-crystal devices. An X-ray imager with a large-size δ-FAPbI wafer integrated on a thin film transistor (TFT) backplane was further fabricated. Direct 2D multipixel radiographic imaging was successfully performed, demonstrating the feasibility of δ-FAPbI wafer detectors for sensitive and ultrastable imaging applications.
卤化物钙钛矿材料具有优异的光电性能，在直接X射线检测方面显示出巨大潜力。钙钛矿晶片在各种检测结构中特别具有吸引力，因为它们具有可扩展性且易于制备，使其成为X射线检测和阵列成像应用中最有前途的候选材料。然而，离子迁移导致的器件不稳定性和电流漂移是钙钛矿探测器持续面临的挑战，尤其是在具有大量晶界的多晶晶片中。在本研究中，我们研究了一维（1D）δ相（黄相）甲脒碘化铅（δ-FAPbI）作为X射线检测材料的潜力。这种材料具有2.43 eV的合适带隙，这使其在使用紧凑型晶片进行X射线检测和成像方面极具前景。此外，我们发现δ-FAPbI具有低离子迁移率、低杨氏模量和出色的长期稳定性，使其成为高性能X射线检测的理想候选材料。值得注意的是，黄相钙钛矿衍生物在六个月内表现出出色的长期大气稳定性（相对湿度约为70±5%），以及极低的暗电流漂移（3.43×10 pA cm s V），这与单晶器件相当。进一步制造了一种在薄膜晶体管（TFT）背板上集成了大尺寸δ-FAPbI晶片的X射线成像器。成功进行了直接二维多像素射线照相成像，证明了δ-FAPbI晶片探测器用于灵敏和超稳定成像应用的可行性。
