Intrinsically‐Stretchable, Efficient Organic Solar Cells Achieved by High‐Molecular‐Weight, Electro‐Active Polymer Acceptor Additives
Abstract
Abstract Organic solar cells (OSCs) are promising wearable/stretchable power sources, but the development of high‐performance intrinsically stretchable OSCs (IS‐OSCs) has rarely been reported. Herein, IS‐OSCs exhibiting high power conversion efficiencies (PCEs) (>12%) and excellent stretchability are developed by constructing efficient and mechanically robust active layers via the addition of a high‐molecular weight polymer acceptor ( P A ) to polymer donor:small‐molecule acceptor blends. P A addition significantly enhances the stretchability and PCEs of the blends as the long P A chains function as molecular bridges between different domains, effectively dissipating mechanical stresses and improving charge transport. The IS‐OSCs with 20 wt% P A content exhibit a high PCE of 11.7% and excellent stretchability, retaining 84% of the initial PCE after 100 cycles of repetitive stretching/releasing at a 15% strain. To the best of the authors’ knowledge, the device represents the best IS‐OSC performance reported to date in terms of PCE and stretchability, demonstrating the great potential of IS‐OSCs as an efficient and wearable power generator.