Dai Hongliang, You Shihai, Ye Huang, Zhu Tingting, Zhu Zeng-Kui, Luo Junhua
School of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, Jiangxi 330022, China.
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
ACS Appl Mater Interfaces. 2024 Aug 14;16(32):42372-42379. doi: 10.1021/acsami.4c04615. Epub 2024 Aug 2.
2D organic-inorganic hybrid perovskites (OIHPs) have shown great promise in direct X-ray detection. The development of high-performance passive X-ray detectors in 2D OIHPs calls for an increase in material density while maintaining structural polarity, which is becoming quite challenging. Here, a high-density, polar 2D alternating-cation-intercalated (ACI) perovskite, (4-AP)CsPbI (, 4-AP = 4-amidinopyridinium), capable of addressing this problem is successfully constructed by introducing heavy Cs into the interlayer space of an aromatic Dion-Jacobson (DJ) perovskite (4-AP)PbI (). Through such a DJ-to-ACI design, the newly developed 2D OIHP not only significantly increases its density to 4.23 g cm (even higher than that of 3D MAPbI) but also crystallizes in a polar space group (2), which further leads to enhanced X-ray attenuation and an obvious polar photovoltage (1.1 V) under X-ray irradiation. As a result, X-ray detectors fabricated by high-quality single crystals of exhibit excellent and stable detection performance under self-powered mode with a high sensitivity of 107 μC Gy cm and a low detection limit of 289 nGy s. This work provides implications for the future exploration and regulation of novel ACI OIHPs for high-performance photoelectronic devices.
二维有机-无机杂化钙钛矿（OIHPs）在直接X射线检测中显示出巨大潜力。在二维OIHPs中开发高性能无源X射线探测器需要在保持结构极性的同时提高材料密度，而这正变得颇具挑战性。在此，通过将重质Cs引入芳香族狄翁-雅各布森（DJ）钙钛矿（4-AP）PbI（）的层间空间，成功构建了一种能够解决该问题的高密度、极性二维交替阳离子插层（ACI）钙钛矿（4-AP）CsPbI（，4-AP = 4-脒基吡啶鎓）。通过这种从DJ到ACI的设计，新开发的二维OIHP不仅将其密度显著提高到4.23 g/cm³（甚至高于三维MAPbI的密度），而且结晶于极性空间群（2）中，这进一步导致X射线衰减增强以及在X射线照射下产生明显的极光伏电压（1.1 V）。结果，由高质量单晶制成的X射线探测器在自供电模式下表现出优异且稳定的检测性能，灵敏度高达107 μC Gy⁻¹ cm²，检测限低至289 nGy s⁻¹。这项工作为未来探索和调控用于高性能光电器件的新型ACI OIHPs提供了启示。
