Solution-Processed Organic Solar Cells with 9.8% Efficiency Based on a New Small Molecule Containing a 2D Fluorinated Benzodithiophene Central Unit

A new small molecule using 2D benzodithiophene with fluorinated thiophene side chains as a central unit, D3RTB-DTTF, is synthesized for highly efficient small molecule solar cells (SM-OSCs). The pristine D3RTBDTTF device shows an efficiency of 9.24%. The efficiency is further increased to 9.80% after a solventvapor annealing process, which is among the top values reported for SM-OSCs.