All-polymer solar cells based on a novel narrow-bandgap polymer acceptor with power conversion efficiency over 10%

A new narrow bandgap polymer acceptor (PN1) based on a fused-ring small molecule acceptor as the core building block was designed and developed. The optimal all-polymer solar cell based on the blend of PM6 and PN1 achieved an outstanding power conversion efficiency of 10.5% with a high open-circuit voltage of 1.0 V, a short circuit current density of 15.2 mA cm⁻² and a fill factor of 0.69.