Achieving long-term operational stability at a high efficiency level for perovskite solar cells is the most challenging issue toward commercialization of this emerging photovoltaic technology. Here, we investigated the cooperation of a Lewis base and a Lewis acid by combining commercial bis-PCBM mixed isomers as the Lewis acid in the antisolvent and N-(4-bromophenyl)thiourea (BrPh-ThR) as the Lewis base in the perovskite solution precursor. The combination of the Lewis base and the Lewis acid synergistically passivates Pb²⁺ and PbX³⁻ antisite defects, enlarges the perovskite grain size, and improves charge-carrier separation and transport, leading to improved device efficiency from 19.3% to 21.7%. In addition, this Lewis base and acid combination also suppresses moisture incursion and passivates pinholes generated in the hole-transporting layer. The unsealed devices remained at 93% of the initial efficiency value in ambient air (10–20% relative humidity) after 3600 h at 20–25 °C and dropped by 10% after 1500 h under continuous operation at 1-sun illumination and 55 °C in nitrogen with maximum power-point tracking.

中文翻译：

---

通过路易斯碱和路易斯酸的协同作用抑制缺陷，从而形成高效，稳定的钙钛矿型太阳能电池†

对于钙钛矿型太阳能电池，要在高效率水平上实现长期的运行稳定性，是该新兴光伏技术商业化面临的最富挑战性的问题。在这里，我们通过结合商业化的双-PCBM混合异构体作为反溶剂中的路易斯酸和N-（4-溴苯基）硫脲（BrPh-ThR）作为钙钛矿中的路易斯碱，研究了路易斯碱和路易斯酸的协同作用。溶液前体。Lewis碱和Lewis酸的组合可协同钝化Pb ²⁺和PbX ^3-抗位缺陷，扩大钙钛矿的晶粒尺寸，并改善载流子的分离和传输，从而将器件效率从19.3％提高到21.7％。另外，该路易斯碱和酸的组合还抑制水分侵入并且钝化在空穴传输层中产生的针孔。在20–25°C下3600小时后，未密封的设备在环境空气（相对湿度为10–20％）中保持为初始效率值的93％，在1个太阳光照和55的连续操作下1500 h后仍下降10％。氮气中的°C，具有最大功率点跟踪。