Han Shiguo, Yao Yunpeng, Liu Xitao, Li Bingxuan, Ji Chengmin, Sun Zhihua, Hong Maochun, Luo Junhua
State Key Laboratory of Structure Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China.
University of Chinese Academy of Sciences, Beijing, 100039, P. R. China.
Small. 2019 Sep;15(39):e1901194. doi: 10.1002/smll.201901194. Epub 2019 Aug 7.
2D hybrid perovskites have shown great promise in the photodetection field, due to their intriguing attributes stemming from unique structural architectures. However, the great majority of detectors based on this 2D system possess a relatively low response speed (≈ms), making it extremely urgent to develop new candidates for superfast photodetection. Here, a new organic-inorganic hybrid perovskite, (PA) (FA)Pb I (EFA, where PA is n-pentylaminium and FA is formamidine), which features the 2D Ruddlesden-Popper type perovskite framework that is composed of the corner-sharing PbI octahedra is reported. Significantly, photodetectors fabricated on highly oriented thin films, which exhibit a perfect orientation parallel to 2D inorganic perovskite layers, exhibit a superfast response time up to ≈2.54 ns. To the best of the knowledge, this figure-of-merit catches up with that of the top-ranking commercial materials, and sets a new record for 2D hybrid perovskite photodetectors. Moreover, extremely high photodetectivity (≈1.73 × 10 Jones, under an incident power intensity of ≈46 µW cm ), considerable switching ratios (>10 ), and low dark current (≈10 pA) are also achieved in the detector, indicating its great potential for high-efficiency photodetection. These results shed light on the possibilities to explore new 2D candidates for assembling future high-performance optoelectronic devices.
二维杂化钙钛矿因其独特结构架构所衍生的有趣特性，在光电探测领域展现出了巨大潜力。然而，基于这种二维体系的绝大多数探测器响应速度相对较低（约毫秒级），这使得开发用于超快速光电探测的新候选材料变得极为迫切。在此，报道了一种新型有机-无机杂化钙钛矿（PA）（FA）PbI（EFA，其中PA为正戊基铵，FA为甲脒），其具有由共角PbI八面体组成的二维Ruddlesden-Popper型钙钛矿框架。值得注意的是，在高度取向的薄膜上制备的光电探测器，其与二维无机钙钛矿层呈现完美的平行取向，展现出高达约2.54纳秒的超快速响应时间。据所知，这一品质因数可与顶级商用材料相媲美，并为二维杂化钙钛矿光电探测器创下了新纪录。此外，该探测器还实现了极高的光探测率（在约46微瓦每平方厘米的入射功率强度下约为1.73×10琼斯）、可观的开关比（>10）以及低暗电流（约10皮安），表明其在高效光电探测方面具有巨大潜力。这些结果为探索用于组装未来高性能光电器件的新型二维候选材料提供了可能性。
