Green‐Solvent‐Processed Scalable Semi‐Transparent Organic Solar Modules with 9.4% Efficiency and 42% Visible Transparency for Energy‐Generating Windows

Abstract Semi‐transparent organic solar cells (ST‐OSCs), designed to selectively absorb UV and NIR light while transmitting visible wavelengths, are highly promising for solar windows and building‐integrated photovoltaics. However, simultaneously achieving high efficiency, transparency, and scalability remains a significant challenge. In this work, green‐solvent‐processed, large‐area solar modules with optimized performance and uniformity is demonstrated. By integrating strategies to reduce non‐radiative recombination losses, a cost‐effective double‐layered nanophotonic structure, and a high‐quality 12‐nm‐thin Ag top electrode, semi‐transparent devices are achieved with a power conversion efficiency of 10.2% and an average visible transmittance of 42%, yielding a light utilization efficiency of 4.2%. Scaling to 5 × 5 cm ² modules, laser scribing, and dead zones, achieving a high geometric fill factor of 96.1%, are optimized. The opaque modules reach an active‐area efficiency of 13.0%, while the semi‐transparent modules achieve 9.4% with AVT > 40%, and demonstrate excellent reproducibility. This work provides a scalable and sustainable pathway for ST‐OSC commercialization and contributes to next‐generation renewable energy solutions.