For semi-transparent perovskite solar cells (PSCs), the bombardment during the deposition of a transparent conductive oxide would inevitably damage the underlying soft materials, thereby inducing a high density of defects and creating an unfavorable band mismatch at the interface. Although interfacial buffer layers can be adopted to alleviate this bombardment damage, the device performance is still limited by the inferior fill factor (FF) due to the increased series resistance and the decreased carrier collection. In this work, a charge transfer induced 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP):Ag complex is employed to mediate the electrical contact between a C₆₀ electron-transport layer and sputtered indium-zinc oxide (IZO) top electrode. We demonstrate that the multifunctional BCP:Ag complex can (1) reduce the electron extraction barrier by pulling up the Fermi level of BCP, (2) create beneficial gap states for electron transport, (3) serve as a hole blocking layer to suppress charge recombination, and (4) protect the C₆₀ underlayer from the sputtering damage. As a result, the optimized electrical contact at the C₆₀/BCP:Ag/IZO interface significantly recovered the FF of the inverted semi-transparent perovskite solar cell from 71.8% to 80.1%, yielding a device efficiency of 18.19%. By using a 23.19% efficient silicon solar cell, we also demonstrate a four-terminal tandem configuration with a total efficiency of 27.59%.

中文翻译：

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电荷转移诱导的多功能BCP：Ag络合物用于半透明钙钛矿太阳能电池，填充率达到创纪录的80.1％

对于半透明钙钛矿太阳能电池（PSC），沉积透明导电氧化物期间的轰击将不可避免地损坏下面的软材料，从而引起高密度的缺陷并在界面处产生不利的谱带失配。尽管可以采用界面缓冲层来减轻这种轰击破坏，但是由于串联电阻增加和载流子收集减少，因此器件性能仍然受到劣质填充因子（FF）的限制。在这项工作中，采用电荷转移诱导的2,9-二甲基-4,7-二苯基-1,10-菲咯啉（BCP）：Ag络合物来介导C ₆₀之间的电接触。电子传输层和溅射的氧化铟锌（IZO）顶部电极。我们证明了多功能BCP：Ag配合物可以（1）通过拉高BCP的费米能级来降低电子提取势垒，（2）创建有利于电子传输的间隙态，（3）用作空穴阻挡层以抑制电荷重组，以及（4）保护C ₆₀底层免受溅射损害。结果，在C ₆₀ / BCP：Ag / IZO界面处的优化电接触可将倒置的半透明钙钛矿太阳能电池的FF从71.8％恢复到80.1％，从而产生18.19％的器件效率。通过使用效率为23.19％的硅太阳能电池，我们还演示了四端子串联配置，总效率为27.59％。