Opening charge transport pathways In perovskite solar cells, the insulating nature of passivation layers needed to boost open-circuit voltage also increases the series resistance of the cell and limits the fill factor. Most improvements in power conversion efficiency have come from higher open-circuit voltage, with most fill factor improvements reported for very small-area cells. Peng et al. used a nanostructured titanium oxide electron transport layer to boost the fill factor of larger-area cells (1 square centimeter) to 0.84 by creating local regions with high conductivity. Science, this issue p. 390 A nanostructured titanium oxide electron transport layer creates local regions of high charge conductivity. Polymer passivation layers can improve the open-circuit voltage of perovskite solar cells when inserted at the perovskite–charge transport layer interfaces. Unfortunately, many such layers are poor conductors, leading to a trade-off between passivation quality (voltage) and series resistance (fill factor, FF). Here, we introduce a nanopatterned electron transport layer that overcomes this trade-off by modifying the spatial distribution of the passivation layer to form nanoscale localized charge transport pathways through an otherwise passivated interface, thereby providing both effective passivation and excellent charge extraction. By combining the nanopatterned electron transport layer with a dopant-free hole transport layer, we achieved a certified power conversion efficiency of 21.6% for a 1-square-centimeter cell with FF of 0.839, and demonstrate an encapsulated cell that retains ~91.7% of its initial efficiency after 1000 hours of damp heat exposure.

中文翻译：

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聚合物钝化钙钛矿太阳能电池中用于高填充因子的纳米级局部接触

打开电荷传输路径 在钙钛矿太阳能电池中，提高开路电压所需的钝化层的绝缘特性也会增加电池的串联电阻并限制填充因子。功率转换效率的大部分改进来自更高的开路电压，据报道，对于非常小面积的电池，填充因子的改进最多。彭等人。使用纳米结构的氧化钛电子传输层，通过创建具有高导电性的局部区域，将大面积电池（1 平方厘米）的填充因子提高到 0.84。科学，这个问题 p。390 纳米结构的氧化钛电子传输层产生高电荷传导性的局部区域。当聚合物钝化层插入钙钛矿-电荷传输层界面时，可以提高钙钛矿太阳能电池的开路电压。不幸的是，许多这样的层是不良导体，导致钝化质量（电压）和串联电阻（填充因子，FF）之间的权衡。在这里，我们引入了一种纳米图案电子传输层，它通过修改钝化层的空间分布以通过其他钝化界面形成纳米级局部电荷传输路径来克服这种权衡，从而提供有效的钝化和出色的电荷提取。通过将纳米图案化电子传输层与不含掺杂剂的空穴传输层相结合，我们实现了 1 平方厘米电池的认证功率转换效率为 21.6%，FF 为 0.839，