The quality of the perovskite absorption layer is critical for the high efficiency and long-term stability of perovskite solar cells (PSCs). The inhomogeneity due to local lattice mismatch causes severe residual strain in low-quality perovskite films, which greatly limits the availability of high-performance PSCs. In this study, a multi-active-site potassium salt, pemirolast potassium (PP), is added to perovskite films to improve carrier dynamics and release residual stress. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) measurements suggest that the proposed multifunctional additive bonds with uncoordinated Pb²⁺ through the carbonyl group/tetrazole N and passivated I atom defects. Moreover, the residual stress release is effective from the surface to the entire perovskite layer, and carrier extraction/transport is promoted in PP-modified perovskite films. As a result, a champion power conversion efficiency (PCE) of 23.06% with an ultra-high fill factor (FF) of 84.36% is achieved in the PP-modified device, which ranks among the best in formamidinium-cesium (FACs) PSCs. In addition, the PP-modified device exhibits excellent thermal stability due to the inhibited phase separation. This work provides a reliable way to improve the efficiency and stability of PSCs by releasing residual stress in perovskite films through additive engineering.

中文翻译：

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吡咯司特钾对高性能倒置钙钛矿太阳能电池载流子管理和应变释放的协同效应

钙钛矿吸收层的质量对于钙钛矿太阳能电池（PSC）的高效率和长期稳定性至关重要。由于局部晶格失配导致的不均匀性导致低质量钙钛矿薄膜中存在严重的残余应变，这极大地限制了高性能PSC的可用性。在这项研究中，将一种多活性位点钾盐——吡嘧司特钾（PP）添加到钙钛矿薄膜中，以改善载流子动力学并释放残余应力。X 射线光电子能谱 (XPS) 和傅里叶变换红外光谱 (FTIR) 测量表明，所提出的多功能添加剂与不配位的 Pb ^2+键合通过羰基/四唑N和钝化的I原子缺陷。此外，残余应力从表面到整个钙钛矿层都有效释放，并且PP改性钙钛矿薄膜中的载流子提取/传输得到促进。结果，PP改性器件实现了23.06%的冠军功率转换效率（PCE）和84.36%的超高填充因子（FF），在甲脒铯（FAC）PSC中名列前茅。 。此外，由于相分离受到抑制，PP改性器件表现出优异的热稳定性。这项工作通过增材工程释放钙钛矿薄膜中的残余应力，为提高PSC的效率和稳定性提供了可靠的方法。