High-efficiency, ultra-flexible organic solar cells enabled by chloroprene rubber as both a non-volatile solid additive and plasticizer

Organic solar cells (OSCs) offer the attraction of mechanical flexibility, enabling unique application scenarios for wearable devices. This study reports the incorporation of chloroprene rubber (CR) as a third component in D18:L8BO OSCs. CR not only serves as a plasticizer that enhances the OSC photoactive film’s stretchability and robustness by incorporating elastomeric chains as well as by promoting three-dimensional non-covalent crosslinking but also acts as a non-volatile additive that enhances D18 molecular packing, thereby increasing the power conversion efficiency (PCE). Thus, rigid substrate OSCs with 5 wt % CR (versus D18 weight reference) exhibit an impressive PCE = 19.25%, and the device containing 50 wt % CR demonstrates both relatively high photovoltaic performance (PCE = 15.95%) and exceptional ductility, exhibiting a crack onset strain of 23.5%. Finally, ultra-flexible OSCs with high performance and mechanical stability are successfully fabricated using 5 wt % CR, achieving a remarkable PCE of 16.91%.