Mechanically Robust All-Polymer Solar Cells from Narrow Band Gap Acceptors with Hetero-Bridging Atoms

摘要： A series of polymer acceptors PF2-DTC, PF2-DTSi, and PF2-DTGe with identical molecular backbone but different central bridging atoms in tricyclic-fused donor units were developed. In all-PSCs, the PF2-DTSi-based blend film exhibited excellent mechanical robustness with an impressively high PCE of up to 10.77%. Moreover, the flexible solar cell based on this blend retained >90% of its initial PCE after bending and relaxing 1,200 times at a bending radius of ~4 mm.