PDF(Pubmed)
Abstract：
The metal halide perovskites exhibit excellent performance as the direct X-ray detectors owing to their strong absorption capability, long carrier lifetime and diffusion length, radiation ruggedness, etc. For imaging applications, the ionic migration of perovskites and charge sharing effect between the adjacent pixels have a significantly negative impact on the spatial resolution. Herein, for the first time, the porous anodic aluminum oxides (AAO) have been used as a template to grow the CsPbBr2I thick film for the direct X-ray detection. Benefiting from the oxygen passivation effect, the activation energy for ionic migration has been observed to increase to 0.701 eV, whereas the dark current drift (1.01 × 10-5 nA cm-1s-1V-1) is one to two orders of magnitude lower than the other lead halide perovskite single crystals and films. Moreover, the AAO insulating wall effectively blocks the charge diffusion effect across a pixel pitch of 10 μm. Overall, the findings reported in this study open a new route for reducing the ionic migration and pixel crosstalk, thus, bringing the perovskite X-ray detectors close to the practical applications.
摘要：
金属卤化物钙钛矿由于其强大的吸收能力，作为直接X射线探测器表现出优异的性能，长载流子寿命和扩散长度，辐射强度，等。对于成像应用，钙钛矿的离子迁移和相邻像素之间的电荷共享效应对空间分辨率有显著的负面影响。在这里，第一次,多孔阳极氧化铝（AAO）已被用作模板来生长CsPbBr2I厚膜以用于直接X射线检测。受益于氧钝化效果，已观察到离子迁移的活化能增加到0.701eV，而暗电流漂移（1.01×10-5nAcm-1s-1V-1）比其他卤化铅钙钛矿单晶和薄膜低一到两个数量级。此外，AAO绝缘壁有效地阻挡跨越10μm的像素间距的电荷扩散效应。总的来说,这项研究报告的发现为减少离子迁移和像素串扰开辟了一条新途径，因此，使钙钛矿X射线探测器接近实际应用。
