Tailoring multifunctional additives for performing interfacial modifications, improving crystallization, and passivating defects is instrumental for the fabrication of efficient and stable perovskite solar cells (PSCs). Here, a Schiff base derivative, (chloromethylene) dimethyliminium chloride (CDCl), is introduced as an additive to modify the interface between the mesoporous TiO₂ electron transport layer and the MAPbI₃ light absorber during the annealing process. CDCl chemically links to TiO₂ and MAPbI₃ through coordination and hydrogen bonding, respectively, and results in the construction of fast electron extraction channels. CDCl also optimizes the energy-level alignment of the TiO₂/MAPbI₃ heterojunction and improves the pore-filling and crystallization of MAPbI₃ in the mesoscopic scaffold, which inhibits nonradiative recombination and eliminates open-circuit voltage losses. As a result, an impressive power conversion efficiency of 19.74%, which is the best one ever reported, is obtained for printable carbon-based hole-conductor-free PSCs based on MAPbI₃.

中文翻译：

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多功能席夫碱衍生物实现创纪录效率的可印刷无孔导体介观钙钛矿太阳能电池

定制多功能添加剂以进行界面改性、改善结晶和钝化缺陷，有助于制造高效稳定的钙钛矿太阳能电池（PSC）。在此，引入席夫碱衍生物（氯亚甲基）二甲基氯化亚胺（CDCl）作为添加剂，以在退火过程中改性介孔TiO ₂电子传输层和MAPbI ₃光吸收剂之间的界面。 CDCl分别通过配位和氢键与TiO ₂和MAPbI ₃化学连接，并导致快速电子提取通道的构建。 CDCl还优化了TiO ₂ /MAPbI ₃异质结的能级排列，并改善了介观支架中MAPbI ₃的孔隙填充和结晶，从而抑制了非辐射复合并消除了开路电压损失。结果，基于 MAPbI ₃的可印刷碳基无空穴导体 PSC 获得了 19.74% 的令人印象深刻的功率转换效率，这是迄今为止报道的最好的效率。