State Key Laboratory of Advanced Chemical Power Sources, Frontiers Science Center for New Organic Matter, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin, P. R. China.
Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada.
Nature. 2024 Nov;635(8037):82-88. doi: 10.1038/s41586-024-08103-7. Epub 2024 Sep 30.
α-FACsPbI is a promising absorbent material for efficient and stable perovskite solar cells (PSCs). However, the most efficient α-FACsPbI PSCs require the inclusion of the additive methylammonium chloride, which generates volatile organic residues (methylammonium) that limit device stability at elevated temperatures. Previously, the highest certified power-conversion efficiency of α-FACsPbI PSCs without methylammonium chloride was only approximately 24% (refs. ), and these PSCs have yet to exhibit any stability advantages. Here we identify interfacial contact loss caused by the accumulation of Cs in conventional α-FACsPbI PSCs, which deteriorates device performance and stability. Through in situ grazing-incidence wide-angle X-ray scattering analysis and density functional theory calculations, we demonstrate an intermediate-phase-assisted crystallization pathway enabled by acetate surface coordination to fabricate high-quality α-FACsPbI films, without using the methylammonium additive. We herein report a certified stabilized power output efficiency of 25.94% and a reverse-scanning power-conversion efficiency of 26.64% for α-FACsPbI PSCs. Moreover, the devices exhibited negligible contact losses and enhanced operational stability. They retained over 95% of their initial power-conversion efficiency after operating for over 2,000 h at the maximum power point under 1 sun, 85 °C and 60% relative humidity (ISOS-L-3).
α-FACsPbI 是一种很有前途的高效稳定钙钛矿太阳能电池（PSC）吸收材料。然而，效率最高的 α-FACsPbI PSCs 需要添加添加剂甲基氯化铵，这会产生挥发性有机残留物（甲基铵），从而限制了器件在高温下的稳定性。此前，不含甲基氯化铵的 α-FACsPbI PSCs 的最高认证功率转换效率仅约为 24%（参考文献），而这些 PSCs 尚未表现出任何稳定性优势。在这里，我们发现传统的 α-FACsPbI PSCs 中由于 Cs 的积累而导致的界面接触损失，这会恶化器件的性能和稳定性。通过原位掠入射广角 X 射线散射分析和密度泛函理论计算，我们证明了一种通过醋酸盐表面配位实现的中间相辅助结晶途径，可以在不使用甲基铵添加剂的情况下制备高质量的 α-FACsPbI 薄膜。我们在此报告了认证的稳定功率输出效率为 25.94%，以及 α-FACsPbI PSCs 的反向扫描功率转换效率为 26.64%。此外，这些器件表现出可忽略的接触损耗和增强的运行稳定性。在 1 个太阳、85°C 和 60%相对湿度（ISOS-L-3）下，在最大功率点下运行超过 2000 小时后，它们的初始功率转换效率保留了超过 95%。
