Stability Effects of Selective Anion Abstraction from Cesium Lead Halide Perovskite Nanocrystals
Stability Effects of Selective Anion Abstraction from Cesium Lead Halide Perovskite Nanocrystals
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DOI：
10.1021/acs.jpcc.2c07017
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发表时间：
2023-01
期刊：
影响因子：
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通讯作者：
Jonathan T. Stoffel;Emily Y. Tsui
中科院分区：
文献类型：
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作者：
Jonathan T. Stoffel;Emily Y. Tsui
铯卤化铅钙钛矿纳米晶(NCS)的动态表面化学和稳定化仍然是这些材料在许多应用中使用的主要挑战。本文用三甲基硅基三氟甲磺酸(Me3SiOTf)作为Lewis酸性试剂，对胶体油酸盐和油胺封端的CsPbBr3和CsPbCl3NCs中的阴离子配体进行了定量和不可逆的硅烷化反应。1H核磁共振和FTIR光谱结合元素分析表明，一组阴离子配体与NC表面有很强的结合。三氟甲磺酸的表面阴离子交换也导致了光致发光量子产率的增加。对于CsPbCl3NCs，Me3SiOTf处理吸收了氯化物，破坏了NC晶格的稳定性。讨论了这些反应之间的热力学差异及其意义。
The dynamic surface chemistry and stabilization of cesium lead halide perovskite nanocrystals (NCs) remain principal challenges for the use of these materials in many applications. Here, trimethylsilyl trifluoromethanesulfonate (Me3SiOTf) was used as a Lewis acidic reagent for quantitative and irreversible silylation and removal of anionic ligands from colloidal oleate- and oleylamine-capped CsPbBr3and CsPbCl3NCs.1H NMR and FTIR spectroscopies, combined with elemental analysis, show strong binding of a population of anionic ligands to the NC surfaces. Surface anion exchange for trifluoromethanesulfonate also results in an increase in photoluminescence quantum yields. For CsPbCl3NCs, Me3SiOTf treatment abstracts chlorides and destabilizes the NC lattice. The thermodynamic differences between these reactions and their implications are discussed.