| 초록 |
PTB7 is a well-known and photoactive benzodithiophene (BDT)-based donor-acceptor polymer. These polymers showed that photovoltaic performance varies depending on the molecular weight. One way to obtain high molecular weight polymers is the microwave-assisted Stille-coupling polymerization, which could increase the molecular weight without changing the PDI. To date, the difference between thermal- and microwave-assisted Stille polymerization methods on PTB7 has not been investigated. In this work, we report a comparative study on thermal- and microwave-assisted Stille coupling polymerization of BDT and fluorinated thieno[3,4-b]thiophene for the synthesis of PTB7 polymers. The microwave-assisted method accelerates homocoupled structural units via aryl-for-aryl exchange during polymerization, which act as charge-trapping sites in polymer solar cells. The increased abundance of these homo-coupled units was demonstrated by various optical spectroscopy methods and the model reaction study. |
