We demonstrate a facile, low-cost and room-temperature method of anion exchange in cesium lead bromide nanocrystals (CsPbBr₃ NCs), embedded into a polymer matrix. The anion exchange occurs upon exposure of the solid CsPbBr₃ NCs/PDMS nanocomposite to a controlled anion precursor gas atmosphere. The rate and extent of the anion exchange reaction can be controlled via the variation of either the exposure time or the relative concentration of the anion precursor gas. Post-synthesis chemical transformation of perovskite nanocrystal–polymer composites is not readily achievable using conventional methods of anion exchange, which renders the gas-assisted strategy extremely useful. We envisage that this work will enable the development of solid-state perovskite NC optoelectronic devices.

中文翻译：

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无机钙钛矿纳米晶体聚合物复合材料中的阴离子交换†

我们展示了一种简便、低成本的室温阴离子交换方法，可将溴化铯铅纳米晶体 (CsPbBr ₃ NCs) 嵌入聚合物基质中。当固体CsPbBr ₃ NCs/PDMS纳米复合材料暴露于受控阴离子前体气体气氛时，阴离子交换发生。阴离子交换反应的速率和程度可以通过改变暴露时间或阴离子前体气体的相对浓度来控制。使用传统的阴离子交换方法不容易实现钙钛矿纳米晶体-聚合物复合材料的合成后化学转化，这使得气体辅助策略非常有用。我们预计这项工作将有助于固态钙钛矿数控光电器件的开发。