Impact of Solvent Additives on Enhancing the Performance and Robustness of Green Solvent‐Processed Indoor Organic Solar Cells

The rapid growth of the Internet of Things increases the demand for efficient indoor organic photovoltaics (OPVs). This study introduces a novel TPD‐3F:FCC‐Cl blend, achieving power conversion efficiencies exceeding 20% and a near 1 V open‐circuit voltage ( V oc ) under 2000Lx illumination. The study examines the blend's potential for indoor energy harvesting, focusing on processing under industrially relevant conditions. The effects of solvent additives, specifically tetralin and diphenyl ether (DPE), are evaluated using spin‐coating and doctor‐blading techniques under both inert and ambient conditions. The use of DPE as a greener additive significantly improves film uniformity, device reproducibility, and performance stability across varying light intensities and layer thicknesses. Structural analysis confirms favorable face‐on orientation and enhanced crystallinity for FCC‐Cl domains, with DPE‐based formulations yielding the most uniform films. Reproducibility metrics further show DPE's superiority over traditional additives, making it promising for industrial‐scale indoor OPV applications. The findings highlight the strong potential of the TPD‐3F:FCC‐Cl blend for high‐efficiency, sustainable indoor OPVs, particularly when processed with non‐halogenated solvents and scalable techniques like blade coating.