Mixed tin/lead (Sn/Pb) perovskites have the potential to achieve higher performances in single junction solar cells compared to Pb-based compounds. The best Sn/Pb based devices are fabricated in a p-i-n structure, and PEDOT:PSS is frequently utilized as the hole transport layer, even if there are many doubts on a possible detrimental role of this conductive polymer. Here, we propose the use of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) and [2-(3, 6-dibromo-9H-carbazol-9-yl) ethyl] phosphonic acid (Br-2PACz) as substitutes for PEDOT:PSS. By using Cs_0.25FA_0.75Sn_0.5Pb_0.5I₃ as the active layer, we obtained record efficiencies as high as 19.51% on Br-2PACz, while 18.44% and 16.33% efficiencies were obtained using 2PACz and PEDOT:PSS, respectively. In addition, the implemented monolayers enhance both the shelf lifetime of the device as well as the operational stability. Finally, the Br-2PACz-based devices maintained 80% of their initial efficiency under continuous illumination for 230 h, and after being stored in a N₂ atmosphere for 4224 h (176 days).

中文翻译：

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基于咔唑的自组装单层作为高效稳定的 Cs0.25FA0.75Sn0.5Pb0.5I3 太阳能电池的空穴传输层

与铅基化合物相比，混合锡/铅 (Sn/Pb) 钙钛矿有可能在单结太阳能电池中实现更高的性能。最好的 Sn/Pb 基器件采用 pin 结构制造，并且 PEDOT:PSS 经常用作空穴传输层，即使人们对这种导电聚合物的可能有害作用存在很多疑问。在这里，我们建议使用 [2-(9 H -carbazol-9-yl)ethyl]phosphonic acid (2PACz) 和 [2-(3, 6-dibromo-9 H -carbazol-9-yl) ethyl] phosphonic acid酸 (Br-2PACz) 作为 PEDOT:PSS 的替代品。通过使用 Cs _0.25 FA _0.75 Sn _0.5 Pb _0.5 I ₃作为活性层，我们在 Br-2PACz 上获得了高达 19.51% 的创纪录效率，而使用 2PACz 和 PEDOT:PSS 分别获得了 18.44% 和 16.33% 的效率。此外，实施的单层增强了设备的保质期和操作稳定性。_{最后，基于 Br-2PACz 的设备在连续光照 230 小时以及在 N 2}气氛中储存4224 小时（176 天）后仍保持其初始效率的 80%。