| 초록 |
Halogenation strategy, which refers introduction of fluorine or chlorine atom to either backbone or side chain of conjugated polymer, is one of the most favored strategies to design highly efficient organic solar cell materials. For donor polymers, many papers are reporting that we can enhance Voc and precisely optimize the blend morphology via halogenation. Here we report a new powerful advantage of halogenation strategy for benzodithiophene-based donor polymer. Large size chlorine atom was verified to help reducing aggregation of rigid polymer backbone, allowing much enhanced solubility to common organic solvent. Thus, it is allowed to fabricate solar cell devices using chlorinated donor polymer with high molecular weight, resulting in high Jsc and FF values. We analyzed blend films fabricated with three different polymers, and concluded that the molecular weight effect is strongly related to excellent photovoltaic performances of chlorinated polymer. |
