瑞士联邦理工学院Kovalenko, Maksym V.研究团队报道了软金属卤化物纳米晶体磷脂封端配体的设计。相关研究成果于2023年12月18日发表于国际一流学术期刊《自然》。

胶体半导体纳米晶体在科学和光电子领域的成功与它们的表面密不可分。卤化铅钙钛矿（LHP）NCs的功能化由于其结构不稳定而带来了巨大的挑战，这与传统半导体NCs的公认共价配体封端不同。研究认为，磷脂作为两性离子表面活性剂广泛而简单的分子工程，可以为金属卤化物NCs提供高度定制的表面化学。分子动力学模拟推断，配体NC的表面亲和力主要由两性离子头基的结构决定，特别是由阴离子和阳离子部分进入表面晶格位点的几何适应度决定，NMR和FTIR数据证实了这一点。

晶格匹配的伯铵磷脂增强了有机-无机杂化LHP（FAPbBr₃和MAPbBr₃，FA甲脒；MA甲基铵），和无铅金属卤化物NCs的结构和胶体完整性。有机配体尾部的分子结构决定了胶体的长期稳定性和与不同极性溶剂的兼容性，从碳氢化合物到丙酮和醇类。这些NCs在溶液和固体中表现出96%以上的光致发光量子产率（PL QY），在单颗粒水平上表现出最小的PL间歇，平均ON分数高达94%，以及明亮和高纯度（约95%）的单光子发射。

附：英文原文

Title: Designer Phospholipid Capping Ligands for Soft Metal Halide Nanocrystals

Author: Morad, Viktoriia, Stelmakh, Andriy, Svyrydenko, Mariia, Feld, Leon G., Boehme, Simon C., Aebli, Marcel, Affolter, Joel, Kaul, Christoph J., Schrenker, Nadine J., Bals, Sara, Sahin, Yesim, Dirin, Dmitry N., Cherniukh, Ihor, Raino, Gabriele, Baumketner, Andrij, Kovalenko, Maksym V.

Issue&Volume: 2023-12-18

Abstract: The success of colloidal semiconductor nanocrystals (NCs) in science and optoelectronics is inextricable from their surfaces. The functionalization of lead halide perovskite (LHP) NCs1–5 poses a formidable challenge due to their structural lability, unlike the well-established covalent ligand-capping of conventional semiconductor NCs6,7. We posited that the vast and facile molecular engineering of phospholipids as zwitterionic surfactants can deliver highly customized surface chemistries for metal halide NCs. Molecular dynamics simulations inferred that ligand-NC surface affinity is primarily governed by the structure of the zwitterionic headgroup, particularly by the geometric fitness of the anionic and cationic moieties into the surface lattice sites, as corroborated by the NMR and FTIR data. Lattice-matched primary-ammonium phospholipids enhance the structural and colloidal integrity of hybrid organic-inorganic LHPs (FAPbBr3 and MAPbBr3, FA-formamidinium; MA-methylammonium) and lead-free metal halide NCs. The molecular structure of the organic ligand tail governs the long-term colloidal stability and compatibility with solvents of diverse polarity, from hydrocarbons to acetone and alcohols. These NCs exhibit photoluminescence quantum yield (PL QY) above 96% in solution and solids and minimal PL intermittency at the single particle level with an average ON fraction as high as 94%, as well as bright and high-purity (ca. 95%) single-photon emission.

DOI: 10.1038/s41586-023-06932-6

Source: https://www.nature.com/articles/s41586-023-06932-6