In-situ Crosslinking and n-Doping of Semiconducting Polymers and Their Application as Efficient Electron-Transporting Materials in Inverted Polymer Solar Cells

In this study, we demonstrate in-situ n-doping and crosslinking of semiconducting polymers as efficient electron-transporting materials for inverted configuration polymer solar cells. The semiconducting polymers were crosslinked with bis(perfluorophenyl) azide (bis-PFPA) to form a robust solvent-resistant film, thereby preventing solvent-induced erosion during subsequent solution-based device processing. In addition, chemical n-doping of semiconducting polymers with (4-(1,3-dimethyl-2,3-dihydro-1H-benzoimidazol-2-yl)phenyl)dimethylamine (N-DMBI) substantially improved the power conversion efficiency of solar cells from 0.69% to 3.42%. These results open the way for progress on generally applicable polymeric interface materials, providing not only high device performance but also an effective fabrication method for solution-processed multilayer solar cell devices.