The stability of perovskite nanocrystals (NCs) is greatly limited due to highly dynamic binding of ligands, which hinders their applications in optoelectronic devices. In this paper, a new ligand strategy was employed to prepare CsPbBr₃ NCs via a facile room temperature (RT) ligand-assisted reprecipitation (LARP) method, where N1.N2-didodecyl-N1.N1.N2.N2-tetramethylethane-1.2-diaminium bromide (DTDB) as the sole capping ligand and an additional Br resource was used. Compared to other ligands with one coordinating group, this class of bidentate ligand can be tightly anchored to the surface of NCs with double N⁺ sites. The as-synthesized DTDB-CsPbBr₃ NCs exhibited a high photoluminescence quantum yield (PLQY) of 92.3% and also showed a superior colloidal stability even under intense purification for up to ten cycles. Compared to the dodecyltrimethyl ammonium bromide (DTAB) ligand capped-CsPbBr₃ NCs, the DTDB-CsPbBr₃ NCs display obviously enhanced stability to light, heat and water. X-ray photoelectron spectroscopy (XPS) results revealed that the DTDB-CsPbBr₃ NCs have a Br⁻ rich surface, which accounts for the high stability and PLQY. Hence, DTDB is a promising ligand to prepare perovskite NCs with higher optical performance.

中文翻译：

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双齿脂肪族季铵配体稳定的 CsPbBr3 钙钛矿纳米晶体，具有高 PLQY (92.3%) 和优异的稳定性

由于配体的高度动态结合，钙钛矿纳米晶体（NCs）的稳定性受到很大限制，这阻碍了它们在光电器件中的应用。在本文中，采用一种新的配体策略通过简便的室温（RT）配体辅助再沉淀（LARP）方法制备CsPbBr 3 NCs，其中N1.N2-二十二烷基-N1.N1.N2.N2-四甲基_乙烷-1.2 -溴化二胺 (DTDB) 作为唯一的封端配体和额外的 Br 资源被使用。与其他具有一个配位基团的配体相比，这类双齿配体可以紧密锚定在具有双N ⁺位点的NCs表面。合成的 DTDB-CsPbBr ₃NCs 表现出 92.3% 的高光致发光量子产率 (PLQY)，即使在多达 10 个循环的强烈纯化下也表现出优异的胶体稳定性。与十二烷基三甲基溴化铵（DTAB）配体封端-CsPbBr ₃ NCs相比，DTDB-CsPbBr ₃ NCs对光、热和水的稳定性明显增强。X 射线光电子能谱 (XPS) 结果表明，DTDB-CsPbBr ₃ NCs 具有富含 Br ^-的表面，这说明了高稳定性和 PLQY。因此，DTDB是制备具有更高光学性能的钙钛矿NCs的有前途的配体。