The quality of the perovskite active layer directly impacts the photovoltaic performance of perovskite solar cells (PSCs). Unfortunately, perovskite films produced through solution methods often have a significant number of defects on their surface, which lead to a substantial degradation in the performance of devices. For this reason, a multifunctional additive 2-(trifluoromethyl) benzimidazole (TFMBI) is introduced into perovskite films. Based on the Lewis acid/base coordination principle, the TFMBI double site cooperatively passivates surface defects, inhibiting carrier non-radiative recombination. Simultaneously, the hydrophobic solid group (−CF₃) of TFMBI covers the surface, establishing a moisture-oxygen barrier and improving the environmental stability of the devices. In consequence, the power conversion efficiency (PCE) of TFMBI-modified PSCs reached 23.16%, significantly higher than the pristine one with a PCE of 20.62%. Additionally, the unencapsulated target device retained 90.32% of its initial PCE even after being reserved in the air with a relative humidity of 20–30% for 60 days.

中文翻译：

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2-(三氟甲基)苯并咪唑对钙钛矿太阳能电池稳定性和性能的协同作用

钙钛矿活性层的质量直接影响钙钛矿太阳能电池（PSC）的光伏性能。不幸的是，通过溶液法生产的钙钛矿薄膜的表面通常存在大量缺陷，这会导致器件性能大幅下降。为此，钙钛矿薄膜中引入了多功能添加剂2-（三氟甲基）苯并咪唑（TFMBI）。基于路易斯酸/碱配位原理，TFMBI双位点协同钝化表面缺陷，抑制载流子非辐射复合。同时，TFMBI的疏水性固体基团（-CF ₃）覆盖表面，建立了湿氧屏障，提高了器件的环境稳定性。结果，TFMBI修饰的PSC的功率转换效率（PCE）达到23.16%，显着高于原始PSC的20.62%的PCE。此外，即使在相对湿度为20-30%的空气中保存60天后，未封装的目标器件仍保留了其初始PCE的90.32%。