Due to the high industrial interest for perovskite-based photovoltaic devices, there is an urgent need to fabricate them under ambient atmosphere, not limited to low relative humidity (RH) conditions. The formamidinium lead iodide (FAPI) perovskite α-black phase is not stable at room temperature and is challenging to stabilize in an ambient environment. In this work, we show that pure FAPI perovskite solar cells (PSCs) have a dramatic increase of device long-term stability when prepared under ambient air compared to FAPI PSCs made under nitrogen, both fabricated with N-methylpyrrolidone (NMP). The T₈₀ parameter, the time in which the efficiency drops to 80% of the initial value, increases from 21 (in N₂) to 112 days (in ambient) to 145 days if PbS quantum dots (QDs) are introduced as additives in air-prepared FAPI PSCs. Furthermore, by adding methylammonium chloride (MACl) the power conversion efficiency (PCE) reaches 19.4% and devices maintain 100% of the original performance for at least 53 days. The presence of Pb–O bonds only in the FAPI films prepared in ambient conditions blocks the propagation of α- to δ-FAPI phase conversion. Thus, these results open the way to a new strategy for the stabilization in ambient air toward perovskite solar cells commercialization.

中文翻译：

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通过环境空气添加剂辅助制造提高纯甲脒钙钛矿太阳能电池的长期稳定性

由于对基于钙钛矿的光伏器件的高度工业兴趣，迫切需要在环境大气下制造它们，而不仅限于低相对湿度 (RH) 条件。甲脒碘化铅 (FAPI) 钙钛矿 α-黑色相在室温下不稳定，在周围环境中难以稳定。在这项工作中，我们表明，与在氮​​气下制备的 FAPI PSC 相比，纯 FAPI 钙钛矿太阳能电池 (PSC) 在环境空气下制备时器件的长期稳定性显着提高，两者均由N-甲基吡咯烷酮 (NMP)制成。所述Ť ₈₀参数，其中，所述效率下降到初始值的80％的时间，从21增大（以N ₂) 到 112 天（在环境中）到 145 天，如果在空气制备的 FAPI PSC 中引入 PbS 量子点 (QD) 作为添加剂。此外，通过添加甲基氯化铵 (MACl)，功率转换效率 (PCE) 达到 19.4%，设备保持 100% 的原始性能至少 53 天。仅在环境条件下制备的 FAPI 薄膜中存在 Pb-O 键会阻止 α- 到 δ-FAPI 相转化的传播。因此，这些结果为稳定环境空气中钙钛矿太阳能电池商业化的新策略开辟了道路。