Li Shufang, Fu Zhengquan, Chen Weikun, Lu Xinhui, Xiang Jiahui, Zhang Jiangbin, Han Kai, Yuan Jun, Zou Yingping
College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
Department of Physics, The Chinese University of Hong Kong, New Territories, Hong Kong 999077, China.
ACS Appl Mater Interfaces. 2025 Jun 18;17(24):35652-35660. doi: 10.1021/acsami.5c08367. Epub 2025 Jun 9.
Inverted organic solar cells (OSCs) exhibit excellent stability, making them promising candidates for practical photovoltaic applications. However, the power conversion efficiency (PCE) of inverted devices still falls behind that of conventionally structured OSCs. In this work, a practical strategy for enhancing inverted device performance is demonstrated by introducing an organosilane-based passivation layer onto the ZnO transport layer via solution processing and thermal cross-linking. During the in situ hydrolysis and condensation process, organosilanes can interact with the oxygen vacancy on the ZnO film to form Zn-O-Si bonds, thereby substantially reducing the surface defects of the ZnO film. Meanwhile, the Si-O-Si network structure formed by the condensation of organosilanes effectively improves hydrophobicity of the interface between ZnO and the active layer, thereby enhancing the stability of the device. When vinyltrimethoxysilane (VTMS) is employed as the passivation layer, the inverted OSCs based on the PM6: BTP-eC9 system achieve a maximum PCE of 18.92%. Furthermore, the VTMS/ZnO-based devices exhibited outstanding stability, owing to the suppressed photocatalytic activity of the ZnO film and the enhanced interfacial hydrophobicity induced by the Si-O-Si network formed through organosilane cross-linking. Following 4224 h of storage in a nitrogen-filled glovebox, the optimized device based on VTMS/ZnO retains 97.42% of its initial PCE. After 330 h of UV exposure, the optimized device could still maintains 91.06% of its initial PCE. These results demonstrate that this method holds great potential for practical applications in high-efficiency and stable inverted OSCs.
倒置型有机太阳能电池（OSCs）具有出色的稳定性，使其成为实际光伏应用的有前途的候选者。然而，倒置型器件的功率转换效率（PCE）仍落后于传统结构的OSCs。在这项工作中，通过溶液处理和热交联在ZnO传输层上引入基于有机硅烷的钝化层，展示了一种提高倒置型器件性能的实用策略。在原位水解和缩合过程中，有机硅烷可以与ZnO薄膜上的氧空位相互作用形成Zn-O-Si键，从而大幅减少ZnO薄膜的表面缺陷。同时，有机硅烷缩合形成的Si-O-Si网络结构有效地改善了ZnO与活性层之间界面的疏水性，从而提高了器件的稳定性。当使用乙烯基三甲氧基硅烷（VTMS）作为钝化层时，基于PM6: BTP-eC9体系的倒置型OSCs实现了18.92%的最大PCE。此外，基于VTMS/ZnO的器件表现出出色的稳定性，这归因于ZnO薄膜光催化活性的抑制以及通过有机硅烷交联形成的Si-O-Si网络诱导的界面疏水性增强。在充满氮气的手套箱中储存4224小时后，基于VTMS/ZnO的优化器件保留了其初始PCE的97.42%。在紫外线照射330小时后，优化器件仍能保持其初始PCE的91.06%。这些结果表明，该方法在高效稳定的倒置型OSCs实际应用中具有巨大潜力。
