Tailoring Surface Chemistry of CsPbI 3 Perovskite Quantum Dots Using Multifunctional Ligand Enables Efficient and Stable Solar Cells

作者：Rufeng Wang, Jian Ni, Jiayi Guan, Shuai Zhang, Miao Yan, Sen Li, Yaofang Zhang, Juan Li, Hongkun Cai, Jianjun Zhang · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2024 · DOI：10.1021/acssuschemeng.4c05956 · 被引用次数：10 · 研究领域：Perovskite Materials and Applications、Quantum Dots Synthesis And Properties、Chalcogenide Semiconductor Thin Films

All-inorganic CsPbI 3 perovskite quantum dots (PQDs) have emerged as promising lighting absorptions for solar cells due to their extraordinary optoelectronic properties and good solution-processability. However, the insulated and dynamic binding characteristics of long-chain ligands on the CsPbI 3 PQD surface still challenge their photovoltaic efficiency and stability. Herein, an effective solution-ligand-exchange strategy is developed to modify the surface chemistry of the CsPbI 3 PQD utilizing 5-aminopyridine-3-carboxylic acid (5A-3C) during the purification process. Systematic analyses reveal that 5A-3C serves as the multifunctional short-chain ligand to exchange long-chain ligands and is strongly bonded to the CsPbI 3 PQD surface, thus facilitating the electronic coupling between neighboring PQDs to promote carrier transport ability. Meanwhile, 5A-3C reduced vacancy defects of the PQD surface and suppressed carrier nonradiation recombination in solar cells. Accordingly, the CsPbI 3 PQD solar cells with 5A-3C treatment exhibit a champion power conversion efficiency (PCE) of 15.03%, significantly higher than that of the control device (13.45%). The operation stability of unencapsulated devices has also been significantly improved. This work offers a deep understanding of PQD surface chemistry and provides a feasible avenue to realize high-performance PQD solar cells.