Tuning Molecular Interactions for Highly Reproducible and Efficient Formamidinium Perovskite Solar Cells via Adduct Approach
Tuning Molecular Interactions for Highly Reproducible and Efficient Formamidinium Perovskite Solar Cells via Adduct Approach
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DOI：
10.1021/jacs.8b01037
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发表时间：
2018-05-23
影响因子：
15
通讯作者：
Yang, Yang
中科院分区：
文献类型：
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作者：
Lee, Jin-Wook;Dai, Zhenghong;Yang, Yang
Lewis酸碱加合法已被广泛用于形成均匀的钙钛矿薄膜，为高性能钙钛矿太阳能电池的开发提供了方法基础。然而，它与甲脒（FA）基钙钛矿的不相容性阻碍了光伏性能和稳定性的进一步提高。在这里，我们报告了一种高效且可重复的方法，通过加合物方法制备高度均匀的FAPbI(3)薄膜。用n -甲基-2-吡咯烷酮（NMP）取代典型的刘易斯碱二甲基亚砜（DMSO），形成稳定的中间加合物相，可转化为均匀且无针孔的FAPbI(3)膜。红外和计算分析表明，NMP与FA阳离子的相互作用比DMSO更强，这有利于形成稳定的FAI-PbI2中心点NMP加合物。根据分子与不同路易斯碱的相互作用，提出了选择路易斯碱的标准。由于薄膜质量高，钙钛矿太阳能电池的最高PCE超过20%（稳定PCE为19.34%），平均PCE为18.83 +/- 0.73%。
The Lewis acid-base adduct approach has been widely used to form uniform perovskite films, which has provided a methodological base for the development of high-performance perovskite solar cells. However, its incompatibility with formamidinium (FA)-based perovskites has impeded further enhancement of photovoltaic performance and stability. Here, we report an efficient and reproducible method to fabricate highly uniform FAPbI(3) films via the adduct approach. Replacement of the typical Lewis base dimethyl sulfoxide (DMSO) with N-methyl-2-pyrrolidone (NMP) enabled the formation of a stable intermediate adduct phase, which can be converted into a uniform and pinhole-free FAPbI(3) film. Infrared and computational analyses revealed a stronger interaction between NMP with the FA cation than DMSO, which facilitates the formation of a stable FAI-PbI2 center dot NMP adduct. On the basis of the molecular interactions with different Lewis bases, we proposed criteria for selecting the Lewis bases. Owed to the high film quality, perovskite solar cells with the highest PCE over 20% (stabilized PCE of 19.34%) and average PCE of 18.83 +/- 0.73% were demonstrated.