Solvent‐Engineering‐Assisted Ligand Exchange Strategy for High‐Efficiency AgBiS 2 Quantum Dot Solar Cells

作者：Qixuan Zhong, Bin Zhao, Yongqiang Ji, Qiuyang Li, Xiaoyu Yang, Mingyu Chu, Yiqi Hu, Lei Li, Shunde Li, Hongyu Xu, Haoming Yan, Tianyu Huang, Peng Chen, H. Chen, Zhangyuchang Lu, Yiming Huangfu, Jiang Wu, Dengke Wang, Ning Wang, Muhan Cao, Qihuang Gong, Rui Zhu, Lichen Zhao · 发表于：Angewandte Chemie International Edition · 年份：2024 · DOI：10.1002/anie.202412590 · 被引用次数：20 · 研究领域：Quantum Dots Synthesis And Properties、Nanocluster Synthesis and Applications、Chalcogenide Semiconductor Thin Films

Abstract As the initial synthesized colloidal quantum dots (CQDs) are generally capped with insulating ligands, ligand exchange strategies are essential in the fabrication of CQD films for solar cells, which can regulate the surface chemical states of CQDs to make them more suitable for thin‐film optoelectronic devices. However, uncontrollable surface adsorption of water molecules during the ligand exchange process introduces new defect sites, thereby impairing the resultant device performance, which attracts more efforts devoted to it but remains a puzzle. Here, we develop a solvent‐engineering‐assisted ligand exchange strategy to revamp the surface adsorption, improve the exchange efficiency, and modulate the surface chemistry for the environmentally friendly lead‐free silver bismuth disulfide (AgBiS 2 ) CQDs. The optimized AgBiS 2 CQD solar cells deliver an outstanding champion power conversion efficiency (PCE) of up to 8.95 % and improved long‐term stability. Our strategy is less environment‐dependent and can produce solar cells with negligible performance variance for several batches across several months. Our work demonstrates the critical role of solvents for ligand exchange in the surface chemistry of CQDs and the realization of high‐performance photovoltaic devices in a highly reproducible manner.