Defect-induced nonradiative recombination limits power conversion efficiency (PCE) of organic–inorganic lead halide perovskite solar cells (PSCs). Recently, molecular passivation methods using ammonium salts and Lewis bases have been gathering tremendous attention for reducing defects at perovskite film surfaces. In this work, we find that an excess amount of 4-tert-butylpyridine (4-tBP), which is used as an additive for an organic hole transport layer, passivates surface defects of perovskite films and, therefore, improves the initial performance of PSCs. In PSCs with this 4-tBP passivation, we achieve very high open circuit voltages of >1.20 V, with a corresponding voltage deficit of 0.38 V, and PCEs of >20%. However, operational stability of PSCs under continuous illumination is greatly decreased. Thus, this work reveals that the 4-tBP passivation causes a trade-off between PCE and operational stability of PSCs.

中文翻译：

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无意钝化 4-叔丁基吡啶以提高钙钛矿太阳能电池的效率并降低其运行稳定性

缺陷诱导的非辐射复合限制了有机-无机卤化铅钙钛矿太阳能电池 (PSC) 的功率转换效率 (PCE)。最近，使用铵盐和路易斯碱的分子钝化方法在减少钙钛矿薄膜表面的缺陷方面受到了极大的关注。在这项工作中，我们发现过量的 4-叔丁基吡啶 (4-tBP)，用作有机空穴传输层的添加剂，钝化钙钛矿薄膜的表面缺陷，从而提高了初始性能PSC。在采用这种 4-tBP 钝化的 PSC 中，我们实现了 >1.20 V 的非常高的开路电压，相应的电压不足为 0.38 V，PCE 为 >20%。然而，PSCs 在连续光照下的运行稳定性大大降低。因此，