Energy‐level modulation between perovskite and carrier transport layers to obtain a promoted carrier extraction and reduced charge recombination is an effective way to achieve high‐efficiency perovskite solar cells. Here, diboron is used as an effective interfacial modifier between SnO₂ and perovskite. By taking advantage of the higher Fermi level on the surface of SnO₂ after diboron treatment, a power‐conversion efficiency of 22.04% in a solar cell device based on two‐step solution‐processed planar n‐i‐p structure is obtained. With the help of thorough characterizations, it is argued that the diboron‐treated SnO₂ exhibits some Sn³⁺ species, which serve as electron donors with a more n‐type nature, promoting electron extraction and reducing carrier recombination in the electron transport layer (ETL)/perovskite interface. Further analysis speculates that the formation of surface diboron–oxygen Lewis pair induces a reducing state of diboron complexes, resulting in the spontaneous electron redistribution and the formation of Sn³⁺−O^–• species. This provides an effective chemical approach to tune the energy alignment between the oxide ETL and absorber.

中文翻译：

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高效钙钛矿型太阳能电池用Diboron改性SnO2中的能级调制

钙钛矿和载流子传输层之间的能级调制以获得促进的载流子提取和减少的电荷复合，是实现高效钙钛矿太阳能电池的有效途径。在此，二硼被用作SnO ₂和钙钛矿之间的有效界面改性剂。通过利用二硼处理后SnO ₂表面较高的费米能级，在基于两步固溶处理的平面n-i-p结构的太阳能电池装置中，功率转换效率为22.04％。在彻底表征的帮助下，有人认为用二硼处理的SnO ₂表现出一些Sn ³⁺物种，可以作为具有更多n型性质的电子供体，促进电子提取并减少电子传输层（ETL）/钙钛矿界面中的载流子复合。进一步的分析推测，表面二价硼-氧路易斯对的形成会诱导二价硼配合物的还原态，从而导致电子自发重新分布并形成Sn ³⁺ -O- ^•物种。这提供了一种有效的化学方法来调节氧化物ETL和吸收剂之间的能量排列。