Abstract Inverted perovskite solar cells based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) have drawn great attention due to their potential for foldable photovoltaic applications. Modification of the interface of PEDOT:PSS and perovskite layer is one of the approaches for improving the efficiency and stability. Here, we introduce a triphenylamine-based small molecule, N,N′-Bis-(1-naphthalenyl)-N,N′-bis-phenyl-(1,1′-biphenyl)-4,4′-diamine (NPB), into the device as the multifunctional buffer layer. It is noted that the NPB buffer layer can obviously reduce the pinholes and defects of perovskite film, and adjust the energy level mismatch between perovskite and PEDOT:PSS layer. Moreover, the carrier recombination of NPB-modified device is restricted due to the reduced defects in perovskite layer and at PEDOT:PSS/perovskite interface. As a result, the device power conversion efficiency is improved from 15.4% to 18.4%. The flexible devices are further fabricated with the best efficiency of 14.4% without hysteresis. Most importantly, due to the superior moisture and UV-light resistance of NPB, the modified device exhibits excellent long-term stability under ambient atmosphere and UV-light soaking.

中文翻译：

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通过在 PEDOT:PSS/钙钛矿界面掺入多功能小分子，提高稳定性的高效灵活太阳能电池

摘要 基于聚（3,4-亚乙基二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT：PSS）的倒置钙钛矿太阳能电池因其在可折叠光伏应用中的潜力而备受关注。PEDOT:PSS与钙钛矿层界面的改性是提高效率和稳定性的方法之一。在这里，我们介绍了一种基于三苯胺的小分子 N,N'-Bis-(1-naphthalenyl)-N,N'-bis-phenyl-(1,1'-biphenyl)-4,4'-diamine (NPB) )，作为多功能缓冲层进入器件。注意到NPB缓冲层可以明显减少钙钛矿薄膜的针孔和缺陷，并调整钙钛矿和PEDOT：PSS层之间的能级失配。此外，由于钙钛矿层和 PEDOT 的缺陷减少，NPB 改性器件的载流子复合受到限制：PSS/钙钛矿界面。因此，器件功率转换效率从 15.4% 提高到 18.4%。进一步制造柔性器件，无滞后的最佳效率为 14.4%。最重要的是，由于 NPB 具有优异的防潮和抗紫外线性能，改进后的器件在环境大气和紫外线浸泡下表现出出色的长期稳定性。