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

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.