Wang Jian, Yu Shanshan, Jin Handong, Li Yu, Zhang Kai, Phillips David Lee, Yang Shihe
Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, Guangdong, 518107, China.
Guangdong Provincial Key Lab of Nano-Micro Materials Research, School of Advanced Materials, Shenzhen Graduate School, Peking University, Shenzhen, Guangdong, 518055, China.
Adv Sci (Weinh). 2024 Dec;11(46):e2407314. doi: 10.1002/advs.202407314. Epub 2024 Oct 21.
Inorganic CsPbBr perovskite emerges as a promising material for the development of next-generation X-ray detectors. However, the formation of a high-quality thick film of CsPbBr has been challenging due to the low solubility of its precursor and its high melting point. To address this limitation, a nonstoichiometry approach is taken that allows lower-temperature crystallization of the target perovskite under the solventless condition. This approach capitalizes on the presence of excess volatile PbBr within the CsPbBr film, which induces melting point depression and promotes recrystallization of CsPbBr at a temperature much lower than its melting point concomitant with the escape of PbBr. Consequently, thick and compact films of CsPbBr are formed with grains ten times larger than those in the pristine films. The resulting X-ray detector exhibits a remarkable sensitivity of 4.2 × 10 µC Gy cm and a low detection limit of 136 nGy s, along with exceptional operational stability. Notably, the CsPbBr-based flat-panel detector achieves a high resolution of 0.65 lp pix and the first demonstration of real-time dynamic X-ray imaging for perovskite-based devices.
无机CsPbBr钙钛矿成为开发下一代X射线探测器的一种有前途的材料。然而，由于其前驱体的低溶解度和高熔点，高质量厚膜CsPbBr的形成一直具有挑战性。为了解决这一限制，采用了一种非化学计量方法，该方法允许在无溶剂条件下使目标钙钛矿在较低温度下结晶。这种方法利用了CsPbBr膜中过量挥发性PbBr的存在，它会导致熔点降低，并促进CsPbBr在远低于其熔点的温度下重结晶，同时PbBr逸出。因此，形成了厚而致密的CsPbBr膜，其晶粒比原始膜中的晶粒大十倍。所得的X射线探测器具有4.2×10 µC Gy cm的显著灵敏度和136 nGy s的低检测限，以及出色的操作稳定性。值得注意的是，基于CsPbBr的平板探测器实现了0.65 lp pix的高分辨率，并首次展示了基于钙钛矿器件的实时动态X射线成像。
