Perovskite solar cells (PSCs) have demonstrated high power conversion efficiency (PCE) but inferior long-term stability and remarkable hysteresis. To date, the most efficient PSCs have a n–i–p device architecture and use Li-TFSI/t-BP as standard bi-dopants for the hole-transporting layer (HTL). However, such dopants not only induce deleterious effects on stability but also significantly affect the hysteresis of PSCs. Here, we demonstrate that a fluorine-containing hydrophobic Lewis acid dopant (LAD) can be employed as an effective dopant for PTAA to realize an exceptional fill factor of 0.81 and a record PCE as high as 19.01%, the highest value among the ever reported PSCs based on a novel dopant in the HTL, versus 17.77% for the control device with Li-TFSI/t-BP doped PTAA. To the best of our knowledge, this is the first case in which a PSC based on a novel dopant for the HTL shows higher efficiency than a PSC based on the state-of-the-art bi-dopants Li-TFSI/t-BP. Besides, the LAD-based PSC displays lower J–V hysteresis and much better long-term stability of up to 70 days under air exposure without encapsulation. We believe that this work will pave a new avenue for high-efficiency, hysteresis-less and stable PSCs exploring hydrophobic dopants as alternatives to hydrophilic Li-TFSI/t-BP.

中文翻译：

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迈向高效，无滞后，稳定的钙钛矿型太阳能电池：使用含氟疏水性路易斯酸对空穴传输材料进行不寻常的掺杂†

钙钛矿太阳能电池（PSC）表现出较高的功率转换效率（PCE），但长期稳定性较差，并具有明显的磁滞现象。迄今为止，最高效的PSC具有i-p设备架构，并使用Li-TFSI / t -BP作为空穴传输层（HTL）的标准双掺杂剂。然而，这些掺杂剂不仅对稳定性造成有害影响，而且还显着影响PSC的滞后性。在这里，我们证明了含氟疏水路易斯酸掺杂剂（LAD）可以用作PTAA的有效掺杂剂，以实现出色的填充因子0.81和创纪录的PCE高达19.01％，这是有史以来报道的最高值HTL中基于新型掺杂剂的PSC，而使用Li-TFSI / t的控制设备的PSC占17.77％-BP掺杂PTAA。据我们所知，这是第一种情况，其中基于用于HTL的新型掺杂剂的PSC的效率要高于基于最新的双掺杂剂Li-TFSI / t -BP的PSC。。此外，基于LAD的PSC在暴露于空气中且没有封装的情况下，显示出更低的J - V磁滞，以及高达70天的长期稳定性。我们认为，这项工作将为探索疏水性掺杂剂替代亲水性Li-TFSI / t -BP的高效，无滞后和稳定的PSC铺平道路。