Fast Anion-Exchange in Highly Luminescent Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, I)

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• 作者：Georgian Nedelcu ; Loredana Protesescu ; Sergii Yakunin ; Maryna I. Bodnarchuk ; Matthias J. Grotevent ; Maksym V. Kovalenko
• 刊名：Nano Letters
• 出版年：2015
• 出版时间：August 12, 2015
• 年：2015
• 卷：15
• 期：8
• 页码：5635-5640
• 全文大小：414K
• ISSN：1530-6992

文摘

Postsynthetic chemical transformations of colloidal nanocrystals, such as ion-exchange reactions, provide an avenue to compositional fine-tuning or to otherwise inaccessible materials and morphologies. While cation-exchange is facile and commonplace, anion-exchange reactions have not received substantial deployment. Here we report fast, low-temperature, deliberately partial, or complete anion-exchange in highly luminescent semiconductor nanocrystals of cesium lead halide perovskites (CsPbX₃, X = Cl, Br, I). By adjusting the halide ratios in the colloidal nanocrystal solution, the bright photoluminescence can be tuned over the entire visible spectral region (410鈥?00 nm) while maintaining high quantum yields of 20鈥?0% and narrow emission line widths of 10鈥?0 nm (from blue to red). Furthermore, fast internanocrystal anion-exchange is demonstrated, leading to uniform CsPb(Cl/Br)₃ or CsPb(Br/I)₃ compositions simply by mixing CsPbCl₃, CsPbBr₃, and CsPbI₃ nanocrystals in appropriate ratios.