Solution-processed quantum dots (QDs) have a high potential for fabricating low-cost, flexible, and large-scale solar energy harvesting devices. It has recently been demonstrated that hybrid devices employing a single monovalent cation perovskite solution for PbS QD surface passivation exhibit enhanced photovoltaic performance when compared to standard ligand passivation. Herein, we demonstrate that the use of a triple cation Cs0.05(MA0.17FA0.83)0.95Pb(I0.9Br0.1)3 perovskite composition for surface passivation of the quantum dots results in highly efficient solar cells, which maintain 96% of their initial performance after 1200 h shelf storage. We confirm perovskite shell formation around the PbS nanocrystals by a range of spectroscopic techniques as well as high-resolution transmission electron microscopy. We find that the triple cation shell results in a favorable energetic alignment to the core of the dot, resulting in reduced recombination due to charge confinement without limiting transport in the active layer. Consequently, photovoltaic devices fabricated via a single-step film deposition reached a maximum AM1.5G power conversion efficiency of 11.3% surpassing most previous reports of PbS solar cells employing perovskite passivation.

中文翻译：

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通过三阳离子钙钛矿钝化技术实现的高效稳定的PbS量子点太阳能电池。

溶液处理的量子点（QD）具有制造低成本，灵活且大规模的太阳能收集设备的巨大潜力。最近已经证明，与标准配体钝化相比，采用单个单价阳离子钙钛矿溶液进行PbS QD表面钝化的混合器件显示出增强的光伏性能。本文中，我们证明了使用三阳离子Cs0.05（MA0.17FA0.83）0.95Pb（I0.9Br0.1）3钙钛矿组合物对量子点进行表面钝化可产生高效的太阳能电池，该太阳能电池可保持96 1200 h货架存储后其初始性能的百分比。我们通过一系列光谱技术以及高分辨率透射电子显微镜确认了PbS纳米晶体周围的钙钛矿壳形成。我们发现，三重阳离子壳层会导致与点核心的良好能量对准，从而由于电荷限制而导致重组减少，而不会限制在活性层中的传输。因此，通过单步膜沉积制造的光伏器件达到了最高AM1.5G功率转换效率11.3％，超过了以前采用钙钛矿钝化的PbS太阳能电池的大多数报道。