Environmental instability of Spiro-OMeTAD-based hole transport layer (HTL) caused due to rapid aggregation and hydration of its additive, Lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), gives rise to an accelerated degradation of the resulting perovskite solar cells (PSCs). Herein, we show that replacing the Li-TFSI with the more hydrophobic alkaline-earth bis(trifluoromethanesulfonyl)imide additives, namely Mg-TFSI₂ and Ca-TFSI₂, can effectively stabilize the coordination complexes between the TFSI-salts and 4-tert-Butylpyridine, which in turn results in retarded additive aggregation and hydration, enabling enhanced moisture-resistance of the subsequent HTLs. Moreover, by manipulating this substitution method, we achieved high-quality HTLs with increased hole mobility, better-formed interface with the adjacent perovskite, allowing improved hole extraction process. Incorporating these HTLs into photovoltaic devices, we obtained a substantial performance improvement, with the champion PSC yielded a power conversion efficiency of over 20%. In addition, un-encapsulated devices stabilized by the alkaline-earth bis(trifluoromethanesulfonyl)imide additive maintained 83% its initial efficiency for 193 days after aging in ambient air (RH% = 55-70%).

由于其添加剂双（三氟甲磺酰基）酰亚胺锂（Li-TFSI）的快速聚集和水合而导致的基于Spiro-OMeTAD的空穴传输层（HTL）的环境不稳定性导致了所产生的钙钛矿太阳能电池的加速降解（ PSC）。在本文中，我们显示了用疏水性更强的碱土金属双（三氟甲磺酰基）酰亚胺添加剂（即Mg-TFSI ₂和Ca-TFSI ₂）代替Li-TFSI可以有效地稳定TFSI盐和4-叔丁基吡啶之间的配位络合物，进而导致添加剂的聚集和水合作用受阻，从而增强后续HTL的耐湿性。此外，通过操纵这种替代方法，我们获得了具有更高空穴迁移率，与相邻钙钛矿的形成更好的界面的高质量HTL，从而改善了空穴提取过程。将这些HTL集成到光伏设备中，我们获得了实质性的性能提升，冠军的PSC产生了超过20％的功率转换效率。此外，在环境空气中老化后，用碱土金属双（三氟甲磺酰基）酰亚胺添加剂稳定的未封装器件在193天后仍保持其初始效率的83％（RH％= 55-70％）。