Stability issues and high material cost constitute the biggest obstacles of a perovskite solar cell (PVSC), hampering its sustainable development. Herein, we demonstrate that, after suitable surface modification, the low-cost cerium oxide (CeO_x) nanocrystals can be well dispersed in both polar and nonpolar solvents and easily processed into high-quality electron transport layers (ETLs). The inverted PVSC with the configuration of “NiMgLiO/MAPbI₃/[6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM)/CeO_x” has achieved a high efficiency up to 18.7%. Especially, the corresponding devices without encapsulation can almost keep their initial PCEs in 30% humidity-controlled air in the dark for 30 days and also show no sign of degradation after continuous light soaking and maximum power point tracking for 200 h in a N₂ atmosphere. These results have been proved to be associated with the dual functions achieved by the PCBM/CeO_x bilayer ETLs in both efficient electron extraction and good chemical shielding. Furthermore, an all inorganic interfacial layer based PVSC with the configuration of “NiMgLiO/MAPbI₃/CeO_x” has also achieved a promising efficiency of 16.7%, reflecting the potential to fabricate efficient PVSCs with extremely low cost.

中文翻译：

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[6,6]-苯基-C _61-丁酸甲基酯/氧化铈双层结构作为钙钛矿型倒置太阳能电池的高效稳定电子输运层

稳定性问题和高昂的材料成本是钙钛矿太阳能电池（PVSC）的最大障碍，阻碍了其可持续发展。在这里，我们证明，经过适当的表面改性后，低成本的氧化铈（CeO _x）纳米晶体可以很好地分散在极性和非极性溶剂中，并且易于加工成高质量的电子传输层（ETL）。具有“ NiMgLiO / MAPbI ₃ / [6,6]-苯基-C _61-丁酸甲酯（PCBM）/ CeO _x ”构型的反向PVSC”达到了高达18.7％的高效率。特别是，没有封装的相应设备几乎可以将其初始PCE在黑暗中于30％湿度控制的空气中保持30天，并且在N ₂气氛中连续浸入光和跟踪最大功率点200 h后也没有降解的迹象。。这些结果已被证明与PCBM / CeO _x双层ETL在有效的电子提取和良好的化学屏蔽方面均具有双重功能有关。此外，具有“ NiMgLiO / MAPbI ₃ / CeO _x ”构型的全无机界面层基PVSC的效率也有望达到16.7％，反映出以极低的成本制造高效PVSC的潜力。