Stable Organic Solar Cells with Enhanced Efficiency Built on Sodium Alginate

Abstract Bulk heterojunction (BHJ) organic solar cells can offer a range of specific advantages, making them suitable for potential integration into a wide variety of applications. This circumstance is driving an ever increasing attention to the environmental profile of this technology throughout its entire life cycle. Consequently, alternative materials and processes with a reduced environmental impact attract interest from researchers focused on developing a new generation of eco‐designed devices. In this context, biomaterials represent an emerging class of sustainable alternatives suitable for use as active and passive components. For instance, some biomaterials can be successfully employed as alternative substrates for flexible solar cells, achieving performances comparable to those of state‐of‐the‐art devices built on plastic. In this work, the preparation of organic solar cells is presented, integrating a water‐processed sodium alginate film as a substrate, with the dual purpose of optimizing the efficiency of the resulting devices and investigating their stability. Specifically, PM6:Y6‐based cells built on SA substrates exhibit a power conversion efficiency that exceeds 10% while showing excellent thermal and mechanical stabilities. These results demonstrate the potential of sodium alginate as a viable candidate for the realization of efficient and stable eco‐designed devices.