Progress Towards Stable Organic Solar Cells

Organic solar cells (OSCs) are suitable candidates for next-generation renewable energy sources due to their low cost of production and flexibility. Their power conversion efficiency has improved significantly to about 20% in both single- and multi-junction devices due to the tremendous work in optimising the synthesis of novel active-layer materials while improving device fabrication. Despite a few reports predicting a 20-year lifetime for OSC devices, their stability currently lags behind their commercialisation. This review discusses the issues that impair OSC stability and how to mitigate them. While emphasising the importance of the International Summit on Organic Photovoltaic Stability (ISOS) protocols, an overview of recent advancements in OSC power conversion efficiency (PCE) and lifetime is provided. A comprehensive list of experimental techniques for studying OSC degradation mechanisms is also extensively discussed, weighing the advantages and disadvantages of different methods. In addition, the review emphasises the importance of essential and cost-effective equipment to encourage impactful contributions especially from resource-limited laboratories, to foster a more inclusive and globally collaborative research landscape, ensuring that diverse scientific perspectives contribute to advancing the field. Finally, fundamental challenges to developing high-performance and stable OSCs are discussed along with general recommendations for improving the stability of OSCs.