High‐Performance Thick‐Film All‐Polymer Solar Cells Enabled by a Blade‐Coating Process Assisted by a Direct Nonuniform Electric Field

Abstract The incorporation of thick active layers (>300 nm) is an essential requirement for wide‐scale industrial production of organic solar cells (OSCs). However, it is still challenging to achieve efficient thick film devices, in particular for all‐polymer OSCs, which are generally considered the most stable type of OSCs. In this study, a simple yet effective method is introduced by using a direct current (DC) field to manipulate the morphology of bulk heterojunction (BHJ) films within all‐polymer OSCs during a blade coating process. By utilizing this method, a favorable vertical phase distribution is achieved, thereby effectively reducing the electron percolation threshold and enhancing the overall device performance. With this, an outstanding efficiency of 17.59% is achieved for thick‐film all‐polymer devices by blade‐coating, which is the best performance in this category. This study introduces a non‐contact DC field method aimed at mitigating the fabrication challenges encountered when transitioning thick‐film all‐polymer systems from laboratory to manufacturing settings, and will potentially contributing to the advancement of the OSC industrialization.