Organometallic perovskite devices have been intensively studied in recent years; however, a comprehensive understanding of their many unique material properties remains to be unveiled. In this work, we demonstrate for the first time a simple, reversible, and non-destructive post-treatment method of anion exchange between CsPbX₃ perovskite nanocrystals (CsPbCl₃ ⇌ CsPbBr₃ ⇌ CsPbI₃) with halogenated solvents, which is mediated by nucleophilic phosphine ligands. Anion exchange between CsPbX₃ perovskite nanocrystals and haloalkane solvents (CHCl₃, CHBr₃, CH₃CH₂I) proceeded readily upon addition of nucleophilic trialkyl phosphines and could be controlled via nucleophile concentration and reaction time, allowing precise tuning of the anion composition and band gap. With our simple method, we obtained luminescence covering the entire visible spectrum from 400 to 700 nm. Furthermore, saturated and vivid RGB LED devices were successfully fabricated using the anion-exchanged nanocrystals.

近年来，对有机金属钙钛矿装置进行了深入研究。然而，对它们许多独特的材料性能的全面理解仍有待揭示。在这项工作中，我们证明首次一个简单的，可逆的，并且CsPbX之间的阴离子交换的非破坏性的后处理方法_3个钙钛矿纳米晶体（CsPbCl ₃ ⇌CsPbBr ₃ ⇌CsPbI ₃与卤化溶剂），这是由亲核介导的膦配体。CsPbX ₃钙钛矿纳米晶体与卤代烷溶剂（CHCl ₃，CHBr ₃，CH ₃ CH _2）之间的阴离子交换I）在添加亲核三烷基膦时容易进行，并且可以通过亲核剂浓度和反应时间来控制，从而允许阴离子组成和带隙的精确调节。使用我们的简单方法，我们获得了覆盖400至700 nm整个可见光谱的发光。此外，使用阴离子交换的纳米晶体成功地制造了饱和和鲜艳的RGB LED器件。