热压模板法制备AAO-CsPbBr2I柱状晶膜及其X射线成像应用

X射线探测在医疗诊断、辐射检测领域应用广泛，突如其来的新冠肺炎更加肯定了X射线成像技术在医学领域应用的重要性。现有X射线直接成像技术存在灵敏度低、成像速度慢、使用剂量高等严重问题，无法实现低辐射损害等实际需求。铯铅溴基X射线探测器具有高灵敏度、低检测限等优异性能，是新一代辐射探测器研究的热点。但在成像应用中，钙钛矿的离子迁移和相邻像素间的电荷共享效应对空间分辨率影响严重。本项目拟利用多孔阳极氧化铝(AAO)为模板，利用微区定向凝固技术生长CsPbBr2I柱状晶，分析其成核生长机理，阐明界面钝化机制；通过理论与实验研究，解析AAO有效阻挡电荷在像素间的扩散行为，建立AAO防串扰作用机制；进一步地，将AAO-CsPbBr2I阵列膜与TFT集成，构建出高灵敏度、暗电流漂移小、低辐射剂量的X射线直接探测器。

X-ray detection has a wide application in areas of medical diagnosis and radiation survey. The sudden arrival of CoviD-19 conforms the importance of X-ray imaging in medical domain. The existing direct X-ray imaging is confronted with serious issues of low detection sensitivity, slow imaging and high radiation dosage, etc, which hardly meet the practical requirement of low radiation damage. CsPbBr3 based X-ray detectors have advantages of high sensitivity, low detection limit and thus is becoming research hotspot for new radiation detectors. However, during the imaging application, the ionic migration of perovskite and charge sharing effect between adjacent pixels make great influence on spatial resolution. In this proposal, the applicant will use anodic AAO as template, grow CsPbBr2I columnar crystal by micro-zone directional solidification technology, analyze the mechanism of nucleation growth and interface passivation. Verify the diffusion behavior of charge between the pixels which can be effectively blocked by AAO, establish the anti-crosstalk mechanism of AAO. Lastly, integrate the AAO-CsPbBr2I array membrane and TFT, construct direct X-ray detector with high sensitivity, low dark current drift and low radiation dosage.