Tegegne, Newayemedhin A.Nchinda, Leonato TambuaKruger, T.P.J. (Tjaart)2025-05-272025-05-272025-02Tegegne, N.A., Nchinda, L.T. & Krüger, T.P.J. 2025, 'Progress toward stable organic solar cells', Advanced Optical Materials, vol. 13, no. 4, art. 2402257, pp. 1-27, doi : 10.1002/adom.202402257.2195-1071 (online)10.1002/adom.202402257http://hdl.handle.net/2263/102529Organic 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 optimizing 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 commercialization. This Review discusses the issues that impair OSC stability and how to mitigate them. While emphasizing 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. Finally, fundamental challenges to developing high-performance and stable OSCs are discussed along with general recommendations for improving the stability of OSCs.en© 2024 The Author(s). Advanced Optical Materials published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License.Organic solar cells (OSCs)Degradation mechanismsISOS protocolsOrganic photovoltaicsInternational Summit on Organic Photovoltaic Stability (ISOS)Article