Interface engineering is widely applied in the one‐step antisolvent deposition for elevating efficiency of the perovskite solar cells (PSCs). Herein, an alcohol‐soluble small molecule, namely 2‐mercaptoimidazole (MI), is inserted between the hole transport layer and perovskite layer to form a cross‐linking bridge, which is built through: i) Coulomb interaction between the negatively charged MI and positively charged poly (3,4‐ethylene dioxythiophene); ii) electrostatic interaction between imidazolium cation and iodide anion in perovskite. The cross‐linking bridge can accelerate the hole transmission and inhibit interfacial recombination. Hence, by the optimum design of MI concentration, hysteresis‐free devices with a high power conversion efficiency of 20.68% are obtained. The overall efficiency increase is due to significantly enhanced short‐circuit current density from 21.28 to 23.45 mA cm⁻² and slightly raised open‐circuit voltage from 1.06 to 1.08 V, suggesting that the MI modified layer can effectively improve the performance of the devices. Moreover, unencapsulated devices with MI interfacial modification show better environmental stability compared to the reference devices. This facile interfacial approach is promising for future commercialization of inverted PSCs.

中文翻译：

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高效钙钛矿太阳能电池接口的小分子调制器，具有高短路电流密度和无滞后性

界面工程广泛应用于一步法反溶剂沉积中，以提高钙钛矿太阳能电池（PSC）的效率。在此，可在空穴传输层和钙钛矿层之间插入可溶于醇的小分子2-巯基咪唑（MI），形成交联桥，该桥可通过以下方式建立：i）带负电的MI与金属之间的库仑相互作用带正电荷的聚（3,4-亚乙基二氧噻吩）; ii）钙钛矿中咪唑阳离子与碘阴离子之间的静电相互作用。交联桥可以加快空穴传输并抑制界面重组。因此，通过MI浓度的优化设计，可获得功率转换效率高达20.68％的无磁滞器件。⁻²并将开路电压从1.06 V略微提高到1.08 V，这表明MI改性层可以有效地改善器件的性能。此外，与参考设备相比，具有MI界面修饰的未封装设备显示出更好的环境稳定性。这种简便的界面方法有望使反向PSC的未来商业化。