Progress in the Stability of Small Molecule Acceptor‐Based Organic Solar Cells

Abstract Significant advancements in power conversion efficiency have been achieved in organic solar cells with small molecule acceptors. However, stability remains a primary challenge, impeding their widespread adoption in renewable energy applications. This review summarizes the degradation of different layers within the device structure in organic solar cells under varying conditions, including light, heat, moisture, and oxygen. For the photoactive layers, the chemical degradation pathways of polymer donors and small molecule acceptors are examined in detail, alongside the morphological stability of the bulk heterojunction structure, which plays a crucial role in device performance. The degradation mechanisms of commonly used anode and cathode interlayers and electrodes are addressed, as these layers significantly influence overall device efficiency and stability. Mitigation methods for the identified degradation mechanisms are provided in each section to offer practical insights for improving device longevity. Finally, an outlook presents the remaining challenges in achieving long‐term stability, emphasizing research directions that require further investigation to enhance the reliability and performance of organic solar cells in real‐world applications.