Publication date: 15th December 2025
The development of organic solar cells requires simultaneous optimization of photovoltaic performance and long-term thermal stability by controlling the bulk heterojunction nanomorphology, which is often mediated by processing solvents and additives. This study investigates the role of small amphiphilic molecules (AMs) as surfactants in stabilizing the bulk heterojunction morphology of PPDT2FBT:PCBM-based organic solar cells. Our research goal is to understand how the chemical nature of AMs and their interface engineering within the device affect stability and efficiency. We demonstrate that the AM's polar headgroup chemistry is a critical determinant for operational stability, and by strategically applying interface engineering across all major interfaces, we identify optimal scenarios for enhancing both efficiency and device durability. Interface engineering not only improves charge transport and mitigates degradation but also supports large-area fabrication and practical device reliability, addressing prominent challenges for commercialization. These findings provide guidance for future molecular design and interface engineering strategies, contributing to the realization of more robust and reliable organic solar cells.
