Chemical interaction at a heterojunction interface induced by an appropriate chemical linker is of crucial importance for high efficiency, hysteresis-less, and stable perovskite solar cells (PSCs). Effective interface engineering in PSCs is reported via a multifunctional chemical linker of 4-imidazoleacetic acid hydrochloride (ImAcHCl) that can provide a chemical bridge between SnO2 and perovskite through an ester bond with SnO2 via esterification reaction and an electrostatic interaction with perovskite via imidazolium cation in ImAcHCl and iodide anion in perovskite. In addition, the chloride anion in ImAcHCl plays a role in the improvement of crystallinity of perovskite film crystallinity. The introduction of ImAcHCl onto SnO2 realigns the positions of the conduction and valence bands upwards, reduces nonradiative recombination, and improves carrier life time. As a consequence, average power conversion efficiency (PCE) is increased from 18.60% ± 0.50% to 20.22% ± 0.34% before and after surface modification, respectively, which mainly results from an enhanced voltage from 1.084 ± 0.012 V to 1.143 ± 0.009 V. The best PCE of 21% is achieved by 0.1 mg mL-1 ImAcHCl treatment, along with negligible hysteresis. Moreover, an unencapsulated device with ImAcHCl-modified SnO2 shows much better thermal and moisture stability than unmodified SnO2 .

中文翻译：

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用于21％高效且稳定的平面钙钛矿太阳能电池的多功能化学连接剂咪唑乙酸盐酸盐。

对于合适的高效，无磁滞和稳定的钙钛矿型太阳能电池（PSC），由适当的化学连接剂诱导的异质结界面处的化学相互作用至关重要。据报道，通过4-咪唑乙酸盐酸盐（ImAcHCl）的多功能化学连接剂可以在PSC中进行有效的界面工程设计，该连接剂可通过酯化反应通过与SnO2的酯键在SnO2和钙钛矿之间提供化学桥，并通过咪唑鎓阳离子与钙钛矿发生静电相互作用。钙钛矿中的ImAcHCl和碘化物阴离子。另外，ImAcHCl中的氯阴离子在钙钛矿膜结晶性的结晶性的提高中起作用。将ImAcHCl引入SnO2可使传导带和价带的位置向上重新排列，从而减少了非辐射复合，并改善了载体的使用寿命。因此，表面改性前后平均功率转换效率（PCE）从18.60％±0.50％提高到20.22％±0.34％，这主要是由于电压从1.084±0.012 V升高到1.143±0.009 V 。0.1 mg mL-1 ImAcHCl处理可实现21％的最佳PCE，且磁滞可忽略不计。而且，具有ImAcHCl改性的SnO2的未封装装置显示出比未改性的SnO2更好的热稳定性和湿气稳定性。以及可忽略的磁滞。而且，具有ImAcHCl改性的SnO2的未封装装置显示出比未改性的SnO2更好的热稳定性和湿气稳定性。以及可忽略的磁滞。而且，具有ImAcHCl改性的SnO2的未封装装置显示出比未改性的SnO2更好的热稳定性和湿气稳定性。