Development of Fluorinated Benzothiadiazole as a Structural Unit for a Polymer Solar Cell of 7 % Efficiency

High-powered polymer: Fluorinated benzothiadiazole was incorporated into a polymer that was used in a high-performance solar cell. The model polymer 2 has decreased HOMO and LUMO energy levels and a similar band gap when compared with its nonfluorinated analogue 1. A bulk heterojunction device derived from 1 demonstrated a high power conversion efficiency of 7.2 % (5.0 % for 1).