Ferroelectric Polymer Drives Performance Enhancement of Non‐fullerene Organic Solar Cells

Abstract

Enhancing the built‐in electric field to promote charge dynamitic process is of great significance to boost the performance of the non‐fullerene organic solar cells (OSCs), which has rarely been concerned. In this work, we introduced a cheap ferroelectric polymer as an additive into the active layers of non‐fullerene OSCs to improve the device performance. An additional and permanent electrical field was produced by the polarization of the ferroelectric dipoles, which can substantially enhance the built‐in electric field. The promoted exciton separation, significantly accelerated charge transport, reduced the charge recombination, as well as the optimized film morphology were observed in the device, leading to a significantly improved performance of the PVDF‐modified OSCs with various active layers, such as PM6 : Y6, PM6 : BTP‐eC9, PM6 : IT‐4F and PTB7‐Th : Y6. Especially, a record efficiency of 17.72 % for PM6 : Y6‐based OSC and an outstanding efficiency of 18.17 % for PM6 : BTP‐eC9‐based OSC were achieved.