Novel Benzo[1,2‐b:4,5‐b′]dithiophene–Benzothiadiazole Derivatives with Variable Side Chains for High‐Performance Solar Cells

Low bandgap copolymers are prepared by incorporating thiophene-modified benzo[1,2-b:4,5-b′]dithiophene and alkyloxy or fluorine-modified benzothiadiazole as donor and acceptor units. These copolymers exhibit a high open-circuit voltage and short-circuit current density. Good power conversion efficiencies are demonstrated in solar cell studies, indicating their promising photovoltaic application as donor materials. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.