Zhang Zheng, Yu Zhixing, Zhao Jiaqi, Zhi Manlong, Dang Wei, Guo Yingnan, Liang Xiaoyang, Mai Yaohua, Li Zhiqiang
Province-Ministry Co-construction Collaborative Innovation Center of Hebei Photovoltaic Technology, College of Physics Science and Technology, Hebei University, Baoding, 071002, China.
Institute of New Energy Technology, College of Physics & Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China.
Small. 2025 Jul;21(29):e2504393. doi: 10.1002/smll.202504393. Epub 2025 May 27.
The performance and stability of wide-band-gap (1.68 eV) perovskite solar cells (PSCs) are critically constrained by two main challenges: i) nonradiative recombination and ii) insufficient environmental stability. In this study, a chemical synergistic passivation strategy is presented, which combines oleic acid (OA) with phenylethylammonium iodide (PEAI). The neutralization reaction between OA and PEAI forms amide groups (─CONH), giving the new passivator (O-PEAI) a high acid dissociation constant (pK). This effectively suppresses the deprotonation of PEA and prevents the formation of PEA₂PbI₄. The amide groups (─CONH) from O-PEAI and the carboxyl groups (─COOH) from OA exert a chemical synergistic passivation effect on surface defects and modulate the surface potential. In comparison with the perovskite films treated by PEAI alone, the carrier lifetime of O-PEAI treated samples increased from 0.179 to 0.270 µs, and the carrier transfer rate between perovskite/PCBM increased sevenfold. The resulting PSCs achieved a champion power conversion efficiency as high as 22.46%. Moreover, due to the hydrophobic alkyl chain of OA, the unencapsulated devices retain 90.4% of their initial efficiency after 1000 h of storage in ambient conditions (40% relative humidity). This study offers a promising pathway for improving the efficiency and durability of wide-band-gap PSCs.
宽带隙（1.68电子伏特）钙钛矿太阳能电池（PSC）的性能和稳定性受到两个主要挑战的严重制约：i）非辐射复合和ii）环境稳定性不足。在本研究中，提出了一种化学协同钝化策略，该策略将油酸（OA）与苯乙铵碘化物（PEAI）相结合。OA与PEAI之间的中和反应形成酰胺基团（─CONH），使新的钝化剂（O-PEAI）具有高酸解离常数（pK）。这有效地抑制了PEA的去质子化，并防止了PEA₂PbI₄的形成。来自O-PEAI的酰胺基团（─CONH）和来自OA的羧基（─COOH）对表面缺陷发挥化学协同钝化作用，并调节表面电位。与仅用PEAI处理的钙钛矿薄膜相比，O-PEAI处理样品的载流子寿命从0.179微秒增加到0.270微秒，钙钛矿/PCBM之间的载流子转移速率提高了七倍。由此制备的PSC实现了高达22.46%的最佳功率转换效率。此外，由于OA的疏水烷基链，未封装的器件在环境条件（相对湿度40%）下储存1000小时后仍保留其初始效率的90.4%。本研究为提高宽带隙PSC的效率和耐久性提供了一条有前景的途径。
