Interfacial engineering is essential for facilitating carrier separation, charge extraction, and enhancing the stability in organic–inorganic perovskite solar cells (PSCs). Herein, a facile and effective method is demonstrated not only to tune the electronic performance of electron transporting layer (ETL) but also to passivate the defects at the interface between the ETL and perovskite. On the top of the tin(IV) oxide (SnO₂) ETL, butylammonium chloride (BACl) and lead(II) iodide (PbI₂) are introduced as interface to modify the ETL/perovskite interface. The PSCs with interface modified exhibit a power conversion efficiency (PCE) of 21.15%, compared to 18.33% for the device without interface modified. Such enhancement in efficiency is mainly attributed to a better energy band alignment, and the quality of perovskite films is improved through the interface modification, thus enhancing photogenerated charge extraction and leading to low charge carrier recombination at the interface of ETL/perovskite. Furthermore, the device with interface modified exhibits significant stability. This work provides an alternative strategy on the ETL/perovskite interface to obtain highly stable and efficient PSCs.

中文翻译：

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通过二维界面能带对准实现高效稳定的钙钛矿太阳能电池

界面工程对于促进载流子分离，电荷提取以及增强有机-无机钙钛矿太阳能电池（PSC）的稳定性至关重要。在本文中，证明了一种简便有效的方法，不仅可以调节电子传输层（ETL）的电子性能，还可以钝化ETL和钙钛矿之间的界面处的缺陷。在氧化锡（IV）（SnO ₂）ETL的顶部，氯化丁基铵（BACl）和碘化铅（II）（PbI ₂）作为接口引入，以修改ETL /钙钛矿接口。经过接口修改的PSC的功率转换效率（PCE）为21.15％，而未经接口修改的设备的功率转换效率为18.33％。这种效率的提高主要归因于更好的能带排列，并且通过界面改性提高了钙钛矿薄膜的质量，从而增强了光生电荷的提取并导致在ETL /钙钛矿的界面处载流子复合低。此外，接口进行了修改的设备显示出显着的稳定性。这项工作为ETL /钙钛矿界面提供了另一种策略，以获得高度稳定和高效的PSC。