The interfacial defects passivation of perovskite is one of the most effective approaches to realize highly efficient and stable perovskite solar cells (PSCs). Herein, we propose an easy in-situ secondary annealing method by using a quaternary ammonium salt tetraethylammonium hexafluorophosphate (TEAH) to enhance the photovoltaic performance and device stability. The research manifests that TEAH can homogeneously distribute on the perovskite surface, and effectively passivate the surface and boundary defects. Correspondingly, the hole extraction from perovskite to the hole transport layer (HTL) is greatly improved, hindering the non-radiative charge carrier recombination. With the introduction of TEAH treatment, the power conversion efficiency (PCE) of the PSC has been elevated from 18.57% to 20.25%, with well suppressed hysteresis. Moreover, the exposed hydrophobic ethyl-terminal groups of TEAH can protect perovskite film from degradation by ambient moisture in some extent. As a result, TEAH treated PSC exhibits good stability, retaining 74.1% of its initial PCE after 680 h aging under ambient air with a relative humidity (RH) of 55–60%.

钙钛矿的界面缺陷钝化是实现高效，稳定的钙钛矿太阳能电池（PSC）的最有效方法之一。本文中，我们提出了一种通过使用季铵盐四乙基六氟磷酸铵（TEAH）来提高光伏性能和器件稳定性的简便原位二次退火方法。研究表明，TEAH可以均匀地分布在钙钛矿表面，并有效钝化表面和边界缺陷。相应地，极大地改善了从钙钛矿到空穴传输层（HTL）的空穴提取，阻碍了非辐射载流子的复合。随着TEAH处理的引入，PSC的功率转换效率（PCE）从18.57％提高到20.25％，并且磁滞得到了很好的抑制。而且，TEAH暴露的疏水性乙基末端基团可以在一定程度上保护钙钛矿膜免受环境湿气的降解。结果，TEAH处理的PSC表现出良好的稳定性，在环境空气中相对湿度（RH）为55-60％老化680小时后，仍保留其初始PCE的74.1％。