Tuning the Optical Properties of Cesium Lead Halide Perovskite Nanocrystals by Anion Exchange Reactions

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• 作者：Quinten A. Akkerman ; Valerio D鈥橧nnocenzo ; Sara Accornero ; Alice Scarpellini ; Annamaria Petrozza ; Mirko Prato ; Liberato Manna
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：August 19, 2015
• 年：2015
• 卷：137
• 期：32
• 页码：10276-10281
• 全文大小：496K
• ISSN：1520-5126

文摘

We demonstrate that, via controlled anion exchange reactions using a range of different halide precursors, we can finely tune the chemical composition and the optical properties of presynthesized colloidal cesium lead halide perovskite nanocrystals (NCs), from green emitting CsPbBr₃ to bright emitters in any other region of the visible spectrum, and back, by displacement of Cl^{鈥?/sup> or I鈥?/sup> ions and reinsertion of Br鈥?/sup> ions. This approach gives access to perovskite semiconductor NCs with both structural and optical qualities comparable to those of directly synthesized NCs. We also show that anion exchange is a dynamic process that takes place in solution between NCs. Therefore, by mixing solutions containing perovskite NCs emitting in different spectral ranges (due to different halide compositions) their mutual fast exchange dynamics leads to homogenization in their composition, resulting in NCs emitting in a narrow spectral region that is intermediate between those of the parent nanoparticles.}