Mei Xinyi, Ren Bainian, Qiu Junming, Sun Zhimei, Zhang Xiaoliang
School of Materials Science and Engineering, Beihang University, Beijing, 100191, China.
Small. 2025 Aug;21(31):e2504748. doi: 10.1002/smll.202504748. Epub 2025 Jun 4.
CsPbI perovskite quantum dots (PQDs) emerge as promising optoelectronic materials for photovoltaics due to their high photoluminescence quantum yields and solution processability. However, the dynamic binding of long-chain ligands on the PQD surface generally induces numerous surface defects, which severely degrade the optoelectronic properties and stability of PQDs, to a large extent limiting the photovoltaic performance and operational stability of PQD solar cells (PQDSCs). Herein, a complementary dual-ligand reconstruction strategy is proposed to resurface the PQDs, in which the trimethyloxonium tetrafluoroborate and phenylethyl ammonium iodide can form a complementary dual-ligand system on the PQD surface through hydrogen bonds. The results reveal that the complementary dual-ligand system can not only stabilize the surface lattice of PQDs maintaining their good dispersion in the colloidal solution but also largely improve the inter-dot electronic coupling in the PQD solids. As a consequence, the PQDs demonstrate substantially improved optoelectronic properties and environmental stability, as well as a more uniform stacking orientation in the PQD solids, leading to a record high efficiency of up to 17.61% being realized in inorganic PQDSCs. This work provides a new avenue for the surface ligand engineering of PQDs for high-performance optoelectronic devices.
CsPbI钙钛矿量子点（PQDs）因其高光致发光量子产率和溶液可加工性而成为有前景的光伏光电器件材料。然而，长链配体在PQD表面的动态结合通常会引发大量表面缺陷，严重降低PQDs的光电性能和稳定性，在很大程度上限制了PQD太阳能电池（PQDSCs）的光伏性能和运行稳定性。在此，提出了一种互补双配体重构策略来重新修饰PQDs表面，其中四氟硼酸三甲氧鎓和苯乙碘化铵可通过氢键在PQD表面形成互补双配体体系。结果表明，该互补双配体体系不仅能稳定PQDs的表面晶格，使其在胶体溶液中保持良好的分散性，还能大幅改善PQD固体中的点间电子耦合。因此，PQDs表现出显著改善的光电性能和环境稳定性，以及在PQD固体中更均匀的堆积取向，从而在无机PQDSCs中实现了高达17.61%的创纪录高效率。这项工作为用于高性能光电器件的PQDs表面配体工程提供了一条新途径。
