Li Mengjia, Ding Jike, Zhang Zuolin, Ma Quanxing, Li Chao, Lu Menghan, Zhang Hong, Pauporté Thierry, Mo Wenlong, Tang Jian-Xin, Chen Jiangzhao, Chen Cong
State Key Laboratory of Reliability and Intelligence of Electrical Equipment, School of Materials Science and Engineering, Hebei University of Technology, Tianjin, 300401, P. R. China.
State Key Laboratory of Photovoltaic Science and Technology, Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Fudan University, Shanghai, P. R. China.
Adv Mater. 2025 Jul;37(27):e2502729. doi: 10.1002/adma.202502729. Epub 2025 May 7.
The instability of perovskite precursor solution induced by deprotonation of organic cations and oxidation of iodide ions substantially deteriorates the reproducibility and reliability of the photovoltaic performance of perovskite solar cells (PSCs). The above decomposition reactions can be conquered via the synergistic engineering of organic functional groups. However, how spatial conformation and type of weak acid functional groups impact the stability of perovskite precursor solution remains to be investigated. Herein, it is uncovered that the position of functional groups on the benzene and the type of weak acid functional groups remarkably influence the acid dissociation constant (pK) and thus the stability of perovskite inks. The pK plays a decisive role in suppressing the deprotonation of organic cations and following the amine-cation addition-elimination reaction. The 4-hydrazinobenzenesulfonic acid (4-HBSA) with the lowest pK is optimal in stabilizing perovskite inks and mitigating nonradiative recombination through defect passivation. This breakthrough enables the inverted PSCs to deliver a power conversion efficiency (PCE) of 26.79% (certified 26.36%, the highest PCE value for PSCs prepared in ambient conditions) using vacuum flash evaporation technology. The modulated PSC could maintain 92% of its initial efficiency after 2000 h of continuous maximum power point tracking.
有机阳离子的去质子化和碘离子的氧化所引发的钙钛矿前驱体溶液的不稳定性，极大地降低了钙钛矿太阳能电池（PSC）光伏性能的可重复性和可靠性。上述分解反应可通过有机官能团的协同工程加以克服。然而，弱酸官能团的空间构象和类型如何影响钙钛矿前驱体溶液的稳定性仍有待研究。在此，我们发现苯环上官能团的位置以及弱酸官能团的类型会显著影响酸解离常数（pK），进而影响钙钛矿油墨的稳定性。pK在抑制有机阳离子的去质子化以及随后的胺阳离子加成-消除反应中起决定性作用。具有最低pK的4-肼基苯磺酸（4-HBSA）在稳定钙钛矿油墨和通过缺陷钝化减轻非辐射复合方面表现最佳。这一突破使得采用真空闪蒸蒸发技术的倒置PSC能够实现26.79%的功率转换效率（PCE）（认证值为26.36%，是在环境条件下制备的PSC的最高PCE值）。经过2000小时的连续最大功率点跟踪后，经过调制的PSC能够保持其初始效率的92%。
