Organoboron Polymer for 10% Efficiency All-Polymer Solar Cells

Optoelectronic polymers are always π-conjugated polymers consisting of C, H, N, S, and O elements. The main group element chemistry is a new tool to tune the optoelectronic properties of polymers. However, the resulting polymers generally show moderate optoelectronic device performance because they cannot meet the multiple requirements for solution-processed devices. Herein, we report an organoboron polymer, which can be used as a polymer acceptor in all-polymer solar cells (all-PSCs) to give power conversion efficiency of as high as 10.1%. By incorporating 2,1,3-benzothiadiazole unit to the organoboron polymer backbone, we tune its absorption spectrum, energy levels, electron mobility, and phase separation behavior. All of these improvements contribute to the excellent all-PSC device performance. These results prove that solution-processed polymers containing main group element atoms can give excellent optoelectronic device performance.