Ji Yongqiang, Wang Minqiang, Yang Zhi, Qiu Hengwei, Kou Song, Padhiar Muhammad Amin, Bhatti Arshad Saleem, Gaponenko Nikolai V
Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education International Center for Dielectric Research, Shannxi Engineering Research Center of Advanced Energy Materials and Devices, Xi'an Jiaotong University, 710049 Xi'an, China.
Centre for Micro and Nano Devices, Department of Physics, COMSATS Institute of Information Technology, Islamabad 44500, Pakistan.
J Phys Chem Lett. 2020 Nov 19;11(22):9862-9868. doi: 10.1021/acs.jpclett.0c02747. Epub 2020 Nov 10.
Very recently, two-dimensional (2D) perovskite nanosheets (PNSs), taking the advantages of perovskite as well as the 2D structure properties, have received an enormous level of interest throughout the scientific community. In spite of this incredible success in perovskite nanocrystals (NCs), self-assembly of many nanostructures in metal halide perovskites has not yet been realized, and producing highly efficient red-emitting PNSs remains challenging. In this Letter, we show that by using CsPbBrI perovskite nanoparticles (NPs) as a building block, PNSs can emerge spontaneously under high ambient pressure via template-free self-assembly without additional complicated operation. It is found that the formation of PNSs is ascribed to the high pressure that provides the driving force for the alignment of NPs in solution. Because of the disappearance of the grain boundaries between the adjacent NPs and increased crystallinity, these PNSs self-assembled from NPs exhibit enhanced properties compared to the initial NPs, including higher PL intensity and remarkable chemical stability toward light and water.
最近，二维（2D）钙钛矿纳米片（PNSs）兼具钙钛矿和二维结构特性的优势，在整个科学界引起了极大关注。尽管钙钛矿纳米晶体（NCs）取得了令人难以置信的成功，但金属卤化物钙钛矿中许多纳米结构的自组装尚未实现，制备高效发红光的PNSs仍然具有挑战性。在本信函中，我们表明，通过使用CsPbBrI钙钛矿纳米颗粒（NPs）作为构建单元，PNSs可以在高环境压力下通过无模板自组装自发出现，无需额外复杂操作。研究发现，PNSs的形成归因于高压为溶液中NPs的排列提供了驱动力。由于相邻NPs之间晶界的消失和结晶度的提高，这些由NPs自组装而成的PNSs与初始NPs相比表现出增强的性能，包括更高的PL强度以及对光和水的显著化学稳定性。
