Sustainable Organic Solar Cells: Materials Review, Molecular Design, and Device Engineering

Organic solar cells (OSCs) have emerged as one of the highly promising avenues in renewable energy due to their lightweight, flexible nature and the potential for low-cost manufacturing. This review provides a comprehensive overview about OSCs processed by halogen-free solvents. First, the state-of-the-art donor and acceptor materials are elaborated, and the design principles for efficient molecules are summarized. Second, the strategies for developing high-performance OSCs processed using nonhalogen solvents are investigated, including solvent engineering for solution pretreatment, thermal processing, and layer-by-layer techniques. Finally, prospects for future research directions are provided, highlighting the need for continuous innovation in nonhalogen solvent-processed OSCs, breaking through existing constraints, and driving the advancement of OSC technologies into the future.