Synergistic ligand mediated anion exchange of CsPbI 3 quantum dots for high performance white LED and anti‐counterfeiting

作者：Yajing Chang, Guoqing Tong, Liping Liu, Junchun Li, Jingting Yang, Zongsheng Chen, Zhigang Li, Shaobo Zhang, Ru Zhou, Yang Jiang · 发表于：EcoMat · 年份：2024 · DOI：10.1002/eom2.12439 · 被引用次数：21 · 研究领域：Perovskite Materials and Applications、Quantum Dots Synthesis And Properties、Chalcogenide Semiconductor Thin Films

Abstract Anion exchange is an effective strategy to regulate the composition and optoelectronic properties of perovskite quantum dots (PQDs). Though promising, it is more desirable to synthesize PQDs to avoid the decrease of photoluminescence quantum yield (PLQY). Herein, we developed a ligand mediated anion exchange approach, in which the phase transition from CsPbBr 3 QDs to CsPbI 3 QDs was observed with the introduction of N‐Acetyl‐ l ‐cysteine (NAC) and 1,3‐dimethylimidazolium iodide (DMII) aqueous solution in CsPbBr 3 QDs solution. NAC is expected to create more halogen vacancies in CsPbBr 3 QDs, which provides sufficient adsorption sites for I − ions, resulting in accelerating the anion exchange rate in the process of DMII incorporation. Benefiting from the synergistic ligand mediated anion exchange, high PLQY of 97% and remarkable stability of CsPbI 3 QDs are obtained. Furthermore, a white light‐emitting diode (WLED) with a lumen efficiency (LE) of 116.82 lm/W is constructed, showing remarkable stability under continuous operation. image