The existence of defects in perovskite films is a major obstacle that prevents perovskite solar cells (PSCs) from high efficiency and long-term stability. A variety of additives have been introduced into perovskite films for reducing the number of defects. Lewis base-based additive engineering has been considered as an effective way to eliminate defects, especially the defects caused by the uncoordinated Pb²⁺. In this work, for the first time, a bilateral cyano molecule (succinonitrile, SN) which is a commonly used plasticizer in solid electrolyte of solid-state lithium batteries was selected as an additive to modify organic–inorganic hybrid perovskite films in PSCs. SN is featured with two cyano groups (–C≡N) distributing at both terminals of the carbon chain, providing two cross-linking points to interact with perovskites crystals via coordinating with uncoordinated Pb²⁺ and forming hydrogen bonds with –NH₂ groups in perovskite. It was found that the addition of SN into perovskite precursor solution could effectively reduce defects, particularly inhabit the appearance of Pb⁰ and thus suppress trap-assisted nonradiative charge carrier recombination. As a result, the efficiency of CH₃NH₃PbI₃(Cl) (MAPbI₃(Cl))-based PSCs was improved from 18.4% to 20.3% with enhanced long-term stability at N₂ and humid air atmosphere. This work provides a facile and effective strategy to enhance the PCE and stability of PSCs simultaneously, facilitating the commercialization of PSCs.

钙钛矿薄膜中缺陷的存在是阻碍钙钛矿太阳能电池（PSC）高效和长期稳定性的主要障碍。为了减少缺陷数量，已将多种添加剂引入钙钛矿薄膜中。基于路易斯碱的添加剂工程被认为是消除缺陷的有效方法，尤其是由于未配位的Pb ²⁺引起的缺陷。。在这项工作中，首次选择了一种双向氰基分子（丁二腈，SN），它是固态锂电池固体电解质中常用的增塑剂，作为添加剂来修饰PSC中的有机-无机杂化钙钛矿薄膜。SN的特征是两个氰基（–C（N）分布在碳链的两个末端，通过与未配位的Pb ^2+配位并与–NH ₂基团形成氢键，提供了两个交联点与钙钛矿晶体相互作用。钙钛矿。发现在钙钛矿前体溶液中添加SN可以有效减少缺陷，特别是出现在Pb ⁰的外观上从而抑制了陷阱辅助的非辐射载流子复合。结果，基于CH ₃ NH ₃ PbI ₃（Cl）（MAPbI ₃（Cl））的PSC的效率从18.4％提高到20.3％，同时在N ₂和潮湿空气中的长期稳定性得到增强。这项工作为同时增强PSC的PCE和稳定性提供了一种简便有效的策略，从而促进了PSC的商业化。