Recent Advances in Single‐Junction Organic Solar Cells Single-junction organic solar cells (OSCs) have made significant progress in recent years. Innovations in material design and device optimization have improved the power conversion efficiencies to over 19 %. In this Minireview, based on recent advances, we discuss molecular design strategies to tune the absorption spectrum, energy level, and intermolecular aggregation as well as highlight the role of molecular electrostatic potential in dec...