Synergistic Multimodal Energy Dissipation Enhances Certified Efficiency of Flexible Organic Photovoltaics beyond 19%

All-polymer organic solar cells (OSCs) have shown unparalleled application potential in the field of flexible wearable electronics in recent years due to the excellent mechanical and photovoltaic properties. However, the small molecule acceptors after polymerization in still retain some mechanical and aggregation properties of the small molecule, falling short of the ductility requirements for flexible devices. Here, based on the multimodal energy dissipation theory, the mechanical and photovoltaic properties of flexible devices are co-enhanced by adding the thermoplastic elastomer material (polyurethane, PU) to the PM6:PBQx-TF:PY-IT-based active layer films. The construction of multi-fiber network structure and the decrease of films' residual stresses contribute to the enhancement of carrier transport properties and the decrease of defect state density. Eventually, the PCE (power conversion efficiency) of 19.40% is achieved on the flexible devices with an effective area of 0.102 cm², and the third-party certified PCE reaches 19.07%, which is the highest PCE for flexible OSCs currently available. To further validate the potential of this strategy for large-area module applications, the 25-cm²-based flexible and super-flexible modules are prepared with the PCEs of 15.48% and 14.61%, respectively, and demonstration applications are implemented.