CsPbBr3 Quantum Dots 2.0: Benzenesulfonic Acid Equivalent Ligand Awakens Complete Purification

作者：Dandan Yang, Xiaoming Li, Wenhan Zhou, Shengli Zhang, Cuifang Meng, Ye Wu, Yue Wang, Haibo Zeng · 发表于：Advanced Materials · 年份：2019 · DOI：10.1002/adma.201900767 · 被引用次数：489 · 研究领域：Perovskite Materials and Applications、Quantum Dots Synthesis And Properties、Luminescence Properties of Advanced Materials

The stability and optoelectronic device performance of perovskite quantum dots (Pe-QDs) are severely limited by present ligand strategies since these ligands exhibit a highly dynamic binding state, resulting in serious complications in QD purification and storage. Here, a "Br-equivalent" ligand strategy is developed in which the proposed strong ionic sulfonate heads, for example, benzenesulfonic acid, can firmly bind to the exposed Pb ions to form a steady binding state, and can also effectively eliminate the exciton trapping probability due to bromide vacancies. From these two aspects, the sulfonate heads play a similar role as natural Br ions in a perfect perovskite lattice. Using this approach, high photoluminescence quantum yield (PL QY) > 90% is facilely achieved without the need for amine-related ligands. Furthermore, the prepared PL QYs are well maintained after eight purification cycles, more than five months of storage, and high-flux photo-irradiation. This is the first report of high and versatile stabilities of Pe-QD, which should enable their improved application in lighting, displays, and biologic imaging.