The operating lifetime under real-world climates is a critical metric to evaluate the commercial potential of any photovoltaic technology. Organic solar cells (OSCs) have experienced rapid breakthroughs in performance over the past decade owing to advances in device and materials engineering, including interfaces, electron acceptors, and donors. However, the intrinsic photodegradation of polymer donors remains poorly understood, and a path to stable OSCs is yet to be demonstrated under outdoor testing conditions. Herein we elucidate the side-chain-induced degradation mechanism in polymer donors and present an outdoor stability database covering 15 representative non-fullerene-based OSCs, supported by in-lab photostability and thermostability analysis. By understanding the performance losses induced by several photoactive layers and interfaces, we demonstrate that encapsulated non-fullerene-based OSCs can retain 91% of the initial efficiency after seven months of operation under hot and sunny Saudi Arabian climates. These findings reveal encouraging prospects of non-fullerene-based OSCs for outdoor applications.

在实际气候下的工作寿命是评估任何光伏技术商业潜力的关键指标。由于器件和材料工程（包括接口、电子受体和供体）的进步，有机太阳能电池 （OSC） 在过去十年中经历了性能的快速突破。然而，对聚合物供体的内在光降解仍然知之甚少，并且在户外测试条件下尚未证明获得稳定 OSC 的途径。在此，我们阐明了聚合物供体中侧链诱导的降解机制，并提出了一个户外稳定性数据库，涵盖 15 种具有代表性的非富勒烯基 OSC，并得到室内光稳定性和热稳定性分析的支持。通过了解几个光活性层和界面引起的性能损失，我们证明，在炎热和阳光明媚的沙特阿拉伯气候下运行七个月后，封装的非富勒烯基 OSC 可以保持 91% 的初始效率。这些发现揭示了非富勒烯基 OSC 在户外应用中的令人鼓舞的前景。